31131731072 has 64 divisors (see below), whose sum is σ = 69094279800. Its totient is φ = 13873004544.

The previous prime is 31131731047. The next prime is 31131731087. The reversal of 31131731072 is 27013713113.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14183857216 + 16947873856 = 119096^2 + 130184^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 274313 + ... + 370824.

Almost surely, 2^31131731072 is an apocalyptic number.

31131731072 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

31131731072 is an abundant number, since it is smaller than the sum of its proper divisors (37962548728).

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

31131731072 is a wasteful number, since it uses less digits than its factorization.

31131731072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645193 (or 645181 counting only the distinct ones).

The product of its (nonzero) digits is 2646, while the sum is 29.

The spelling of 31131731072 in words is "thirty-one billion, one hundred thirty-one million, seven hundred thirty-one thousand, seventy-two".