31520661 has 16 divisors (see below), whose sum is σ = 42780864. Its totient is φ = 20640384.

The previous prime is 31520659. The next prime is 31520701. The reversal of 31520661 is 16602513.

It is not a de Polignac number, because 31520661 - 2¹ = 31520659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31520761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68745 + ... + 69201.

It is an arithmetic number, because the mean of its divisors is an integer number (2673804).

Almost surely, 2^31520661 is an apocalyptic number.

It is an amenable number.

31520661 is a deficient number, since it is larger than the sum of its proper divisors (11260203).

31520661 is a wasteful number, since it uses less digits than its factorization.

31520661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 31520661 is about 5614.3264066137. The cubic root of 31520661 is about 315.8870136308.

The spelling of 31520661 in words is "thirty-one million, five hundred twenty thousand, six hundred sixty-one".