31931145 has 16 divisors (see below), whose sum is σ = 56766720. Its totient is φ = 17029872.

The previous prime is 31931071. The next prime is 31931167. The reversal of 31931145 is 54113913.

It is not a de Polignac number, because 31931145 - 2¹⁰ = 31930121 is a prime.

It is a super-2 number, since 2×31931145² = 2039196042022050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118129 + ... + 118398.

It is an arithmetic number, because the mean of its divisors is an integer number (3547920).

Almost surely, 2^31931145 is an apocalyptic number.

It is an amenable number.

31931145 is a deficient number, since it is larger than the sum of its proper divisors (24835575).

31931145 is a wasteful number, since it uses less digits than its factorization.

31931145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236541 (or 236535 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 31931145 is about 5650.7649924590. The cubic root of 31931145 is about 317.2523375021.

The spelling of 31931145 in words is "thirty-one million, nine hundred thirty-one thousand, one hundred forty-five".