31897 has 4 divisors (see below), whose sum is σ = 32256. Its totient is φ = 31540.

The previous prime is 31891. The next prime is 31907. The reversal of 31897 is 79813.

31897 is nontrivially palindromic in base 12.

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 31897 - 2⁷ = 31769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31891) 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, 72 + ... + 262.

It is an arithmetic number, because the mean of its divisors is an integer number (8064).

2³¹⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

31897 is a deficient number, since it is larger than the sum of its proper divisors (359).

31897 is a wasteful number, since it uses less digits than its factorization.

31897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358.

The product of its digits is 1512, while the sum is 28.

The square root of 31897 is about 178.5973124098. The cubic root of 31897 is about 31.7139214462.

Multiplying 31897 by its sum of digits (28), we get a triangular number (893116 = T₁₃₃₆).

The spelling of 31897 in words is "thirty-one thousand, eight hundred ninety-seven".