31213197 has 6 divisors (see below), whose sum is σ = 45085742. Its totient is φ = 20808792.

The previous prime is 31213159. The next prime is 31213201. The reversal of 31213197 is 79131213.

It can be written as a sum of positive squares in only one way, i.e., 31203396 + 9801 = 5586^2 + 99^2 .

It is not a de Polignac number, because 31213197 - 2⁷ = 31213069 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31213197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31213157) 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 5 ways as a sum of consecutive naturals, for example, 1734058 + ... + 1734075.

Almost surely, 2^31213197 is an apocalyptic number.

It is an amenable number.

31213197 is a deficient number, since it is larger than the sum of its proper divisors (13872545).

31213197 is a wasteful number, since it uses less digits than its factorization.

31213197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3468139 (or 3468136 counting only the distinct ones).

The product of its digits is 1134, while the sum is 27.

The square root of 31213197 is about 5586.8772136141. The cubic root of 31213197 is about 314.8565635694.

The spelling of 31213197 in words is "thirty-one million, two hundred thirteen thousand, one hundred ninety-seven".