31131906 has 32 divisors (see below), whose sum is σ = 69370560. Its totient is φ = 9248064.

The previous prime is 31131887. The next prime is 31131929. The reversal of 31131906 is 60913113.

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, 4620 + ... + 9143.

It is an arithmetic number, because the mean of its divisors is an integer number (2167830).

Almost surely, 2^31131906 is an apocalyptic number.

31131906 is an abundant number, since it is smaller than the sum of its proper divisors (38238654).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31131906 is a wasteful number, since it uses less digits than its factorization.

31131906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13810.

The product of its (nonzero) digits is 486, while the sum is 24.

The square root of 31131906 is about 5579.5972972966. The cubic root of 31131906 is about 314.5829906443.

The spelling of 31131906 in words is "thirty-one million, one hundred thirty-one thousand, nine hundred six".