31138865815540 has 72 divisors (see below), whose sum is σ = 76069157905440. Its totient is φ = 10675992091968.

The previous prime is 31138865815537. The next prime is 31138865815543. The reversal of 31138865815540 is 4551856883113.

It is an interprime number because it is at equal distance from previous prime (31138865815537) and next prime (31138865815543).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31138865815543) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61553751 + ... + 62057569.

It is an arithmetic number, because the mean of its divisors is an integer number (1056516082020).

Almost surely, 2^{31138865815540} is an apocalyptic number.

It is an amenable number.

31138865815540 is an abundant number, since it is smaller than the sum of its proper divisors (44930292089900).

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

31138865815540 is a wasteful number, since it uses less digits than its factorization.

31138865815540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566909 (or 566900 counting only the distinct ones).

The product of its (nonzero) digits is 13824000, while the sum is 58.

The spelling of 31138865815540 in words is "thirty-one trillion, one hundred thirty-eight billion, eight hundred sixty-five million, eight hundred fifteen thousand, five hundred forty".