31640669 has 2 divisors, whose sum is σ = 31640670. Its totient is φ = 31640668.

The previous prime is 31640659. The next prime is 31640671. The reversal of 31640669 is 96604613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22562500 + 9078169 = 4750^2 + 3013^2 .

It is a cyclic number.

It is not a de Polignac number, because 31640669 - 2¹² = 31636573 is a prime.

It is a super-2 number, since 2×31640669² = 2002263869535122, which contains 22 as substring.

Together with 31640671, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31640659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15820334 + 15820335.

It is an arithmetic number, because the mean of its divisors is an integer number (15820335).

Almost surely, 2^31640669 is an apocalyptic number.

It is an amenable number.

31640669 is a deficient number, since it is larger than the sum of its proper divisors (1).

31640669 is an equidigital number, since it uses as much as digits as its factorization.

31640669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 31640669 is about 5625.0039111098. The cubic root of 31640669 is about 316.2873960996.

The spelling of 31640669 in words is "thirty-one million, six hundred forty thousand, six hundred sixty-nine".