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31428 = 223497
BaseRepresentation
bin111101011000100
31121010000
413223010
52001203
6401300
7160425
oct75304
947100
1031428
1121681
1216230
13113c7
14b64c
1594a3
hex7ac4

31428 has 30 divisors (see below), whose sum is σ = 83006. Its totient is φ = 10368.

The previous prime is 31397. The next prime is 31469. The reversal of 31428 is 82413.

It can be divided in two parts, 3 and 1428, that added together give a triangular number (1431 = T53).

It is a happy number.

31428 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 26244 + 5184 = 162^2 + 72^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a lonely number, since its distance to closest prime (31397) sets a new record.

It is a self number, because there is not a number n which added to its sum of digits gives 31428.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 31428.

It is an unprimeable number.

31428 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 276 + ... + 372.

231428 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41503).

31428 is an abundant number, since it is smaller than the sum of its proper divisors (51578).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31428 is a wasteful number, since it uses less digits than its factorization.

31428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 102 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 31428 is about 177.2794404323. The cubic root of 31428 is about 31.5577173095.

The spelling of 31428 in words is "thirty-one thousand, four hundred twenty-eight".

Divisors: 1 2 3 4 6 9 12 18 27 36 54 81 97 108 162 194 291 324 388 582 873 1164 1746 2619 3492 5238 7857 10476 15714 31428