31530997 has 6 divisors (see below), whose sum is σ = 32283222. Its totient is φ = 30795912.

The previous prime is 31530979. The next prime is 31531001. The reversal of 31530997 is 79903513.

It can be written as a sum of positive squares in only one way, i.e., 25310961 + 6220036 = 5031^2 + 2494^2 .

It is a de Polignac number, because none of the positive numbers 2^k-31530997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31530977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6678 + ... + 10375.

It is an arithmetic number, because the mean of its divisors is an integer number (5380537).

Almost surely, 2^31530997 is an apocalyptic number.

It is an amenable number.

31530997 is a deficient number, since it is larger than the sum of its proper divisors (752225).

31530997 is an equidigital number, since it uses as much as digits as its factorization.

31530997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17139 (or 17096 counting only the distinct ones).

The product of its (nonzero) digits is 25515, while the sum is 37.

The square root of 31530997 is about 5615.2468333992. The cubic root of 31530997 is about 315.9215375616.

The spelling of 31530997 in words is "thirty-one million, five hundred thirty thousand, nine hundred ninety-seven".