31257345 has 72 divisors (see below), whose sum is σ = 62150976. Its totient is φ = 13349952.

The previous prime is 31257311. The next prime is 31257349. The reversal of 31257345 is 54375213.

It is not a de Polignac number, because 31257345 - 2⁸ = 31257089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31257349) 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 71 ways as a sum of consecutive naturals, for example, 726894 + ... + 726936.

It is an arithmetic number, because the mean of its divisors is an integer number (863208).

Almost surely, 2^31257345 is an apocalyptic number.

31257345 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31257345 is a deficient number, since it is larger than the sum of its proper divisors (30893631).

31257345 is a wasteful number, since it uses less digits than its factorization.

31257345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 81 counting only the distinct ones).

The product of its digits is 12600, while the sum is 30.

The square root of 31257345 is about 5590.8268619230. The cubic root of 31257345 is about 315.0049381942.

The spelling of 31257345 in words is "thirty-one million, two hundred fifty-seven thousand, three hundred forty-five".