31540861 has 4 divisors (see below), whose sum is σ = 34408224. Its totient is φ = 28673500.

The previous prime is 31540837. The next prime is 31540867. The reversal of 31540861 is 16804513.

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.

It is a cyclic number.

It is not a de Polignac number, because 31540861 - 2¹⁵ = 31508093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31540867) 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, 1433665 + ... + 1433686.

It is an arithmetic number, because the mean of its divisors is an integer number (8602056).

Almost surely, 2^31540861 is an apocalyptic number.

It is an amenable number.

31540861 is a deficient number, since it is larger than the sum of its proper divisors (2867363).

31540861 is a wasteful number, since it uses less digits than its factorization.

31540861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2867362.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 31540861 is about 5616.1250876383. The cubic root of 31540861 is about 315.9544779001.

The spelling of 31540861 in words is "thirty-one million, five hundred forty thousand, eight hundred sixty-one".