31887697 has 4 divisors (see below), whose sum is σ = 31915620. Its totient is φ = 31859776.

The previous prime is 31887679. The next prime is 31887703. The reversal of 31887697 is 79678813.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79678813 = 17 ⋅4686989.

It can be written as a sum of positive squares in 2 ways, for example, as 18352656 + 13535041 = 4284^2 + 3679^2 .

It is a cyclic number.

It is not a de Polignac number, because 31887697 - 2¹⁵ = 31854929 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31887697.

It is not an unprimeable number, because it can be changed into a prime (31887997) 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, 12172 + ... + 14557.

It is an arithmetic number, because the mean of its divisors is an integer number (7978905).

Almost surely, 2^31887697 is an apocalyptic number.

It is an amenable number.

31887697 is a deficient number, since it is larger than the sum of its proper divisors (27923).

31887697 is a wasteful number, since it uses less digits than its factorization.

31887697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27922.

The product of its digits is 508032, while the sum is 49.

The square root of 31887697 is about 5646.9192485815. The cubic root of 31887697 is about 317.1083794517.

The spelling of 31887697 in words is "thirty-one million, eight hundred eighty-seven thousand, six hundred ninety-seven".