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30997 = 139223
BaseRepresentation
bin111100100010101
31120112001
413210111
51442442
6355301
7156241
oct74425
946461
1030997
112131a
1215b31
1311155
14b421
1592b7
hex7915

30997 has 4 divisors (see below), whose sum is σ = 31360. Its totient is φ = 30636.

The previous prime is 30983. The next prime is 31013. The reversal of 30997 is 79903.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 30997 - 27 = 30869 is a prime.

It is a Duffinian number.

30997 is a lucky number.

It is a plaindrome in base 13.

It is a nialpdrome in base 14.

It is a zygodrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28 + ... + 250.

It is an arithmetic number, because the mean of its divisors is an integer number (7840).

230997 is an apocalyptic number.

It is an amenable number.

30997 is a deficient number, since it is larger than the sum of its proper divisors (363).

30997 is a wasteful number, since it uses less digits than its factorization.

30997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362.

The product of its (nonzero) digits is 1701, while the sum is 28.

The square root of 30997 is about 176.0596489830. The cubic root of 30997 is about 31.4127931426.

It can be divided in two parts, 309 and 97, that added together give a triangular number (406 = T28).

The spelling of 30997 in words is "thirty thousand, nine hundred ninety-seven".

Divisors: 1 139 223 30997