31561401655424 has 32 divisors (see below), whose sum is σ = 64575587433900. Its totient is φ = 15354195397632.

The previous prime is 31561401655403. The next prime is 31561401655457. The reversal of 31561401655424 is 42455610416513.

It can be written as a sum of positive squares in 2 ways, for example, as 27749379701824 + 3812021953600 = 5267768^2 + 1952440^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×31561401655424² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3332068919 + ... + 3332078390.

Almost surely, 2^{31561401655424} is an apocalyptic number.

It is an amenable number.

31561401655424 is an abundant number, since it is smaller than the sum of its proper divisors (33014185778476).

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

31561401655424 is an equidigital number, since it uses as much as digits as its factorization.

31561401655424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6664147360 (or 6664147348 counting only the distinct ones).

The product of its (nonzero) digits is 1728000, while the sum is 47.

The spelling of 31561401655424 in words is "thirty-one trillion, five hundred sixty-one billion, four hundred one million, six hundred fifty-five thousand, four hundred twenty-four".