31520973 has 16 divisors (see below), whose sum is σ = 46826496. Its totient is φ = 18696240.

The previous prime is 31520959. The next prime is 31520977. The reversal of 31520973 is 37902513.

It is not a de Polignac number, because 31520973 - 2¹⁷ = 31389901 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31520973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31520977) 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, 8611 + ... + 11712.

It is an arithmetic number, because the mean of its divisors is an integer number (2926656).

Almost surely, 2^31520973 is an apocalyptic number.

31520973 is a gapful number since it is divisible by the number (33) formed by its first and last digit.

It is an amenable number.

31520973 is a deficient number, since it is larger than the sum of its proper divisors (15305523).

31520973 is a wasteful number, since it uses less digits than its factorization.

31520973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20384.

The product of its (nonzero) digits is 5670, while the sum is 30.

The square root of 31520973 is about 5614.3541926031. The cubic root of 31520973 is about 315.8880558723. Note that the first 3 decimals are identical.

The spelling of 31520973 in words is "thirty-one million, five hundred twenty thousand, nine hundred seventy-three".