31660531 has 4 divisors (see below), whose sum is σ = 36183472. Its totient is φ = 27137592.

The previous prime is 31660507. The next prime is 31660537. The reversal of 31660531 is 13506613.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31660531 - 2¹⁵ = 31627763 is a prime.

It is a super-2 number, since 2×31660531² = 2004778446403922, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 31660496 and 31660505.

It is not an unprimeable number, because it can be changed into a prime (31660537) 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, 2261460 + ... + 2261473.

It is an arithmetic number, because the mean of its divisors is an integer number (9045868).

Almost surely, 2^31660531 is an apocalyptic number.

31660531 is a deficient number, since it is larger than the sum of its proper divisors (4522941).

31660531 is an equidigital number, since it uses as much as digits as its factorization.

31660531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4522940.

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 31660531 is about 5626.7691440115. The cubic root of 31660531 is about 316.3535639612.

The spelling of 31660531 in words is "thirty-one million, six hundred sixty thousand, five hundred thirty-one".