31640621 has 8 divisors (see below), whose sum is σ = 33609024. Its totient is φ = 29684160.

The previous prime is 31640611. The next prime is 31640659. The reversal of 31640621 is 12604613.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31640621 is a prime.

It is a super-2 number, since 2×31640621² = 2002257794531282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31640611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2816 + ... + 8438.

It is an arithmetic number, because the mean of its divisors is an integer number (4201128).

Almost surely, 2^31640621 is an apocalyptic number.

It is an amenable number.

31640621 is a deficient number, since it is larger than the sum of its proper divisors (1968403).

31640621 is a wasteful number, since it uses less digits than its factorization.

31640621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5971.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 31640621 is about 5624.9996444444. Note that the first 3 decimals coincide. The cubic root of 31640621 is about 316.2872361598.

The spelling of 31640621 in words is "thirty-one million, six hundred forty thousand, six hundred twenty-one".