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31040 = 26597
BaseRepresentation
bin111100101000000
31120120122
413211000
51443130
6355412
7156332
oct74500
946518
1031040
1121359
1215b68
1311189
14b452
1592e5
hex7940

31040 has 28 divisors (see below), whose sum is σ = 74676. Its totient is φ = 12288.

The previous prime is 31039. The next prime is 31051. The reversal of 31040 is 4013.

Adding to 31040 its reverse (4013), we get a palindrome (35053).

It can be written as a sum of positive squares in 2 ways, for example, as 12544 + 18496 = 112^2 + 136^2 .

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272 + ... + 368.

It is an arithmetic number, because the mean of its divisors is an integer number (2667).

231040 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 31040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37338).

31040 is an abundant number, since it is smaller than the sum of its proper divisors (43636).

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

31040 is an equidigital number, since it uses as much as digits as its factorization.

31040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 8.

The square root of 31040 is about 176.1817243644. The cubic root of 31040 is about 31.4273120314.

The spelling of 31040 in words is "thirty-one thousand, forty".

Divisors: 1 2 4 5 8 10 16 20 32 40 64 80 97 160 194 320 388 485 776 970 1552 1940 3104 3880 6208 7760 15520 31040