31331120400 has 90 divisors (see below), whose sum is σ = 108727703370. Its totient is φ = 8354964480.

The previous prime is 31331120371. The next prime is 31331120417. The reversal of 31331120400 is 402113313.

31331120400 is a `hidden beast` number, since 313 + 311 + 2 + 0 + 40 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 400160016 + 30930960384 = 20004^2 + 175872^2 .

It is a tau number, because it is divible by the number of its divisors (90).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4347945 + ... + 4355144.

It is an arithmetic number, because the mean of its divisors is an integer number (1208085593).

Almost surely, 2^31331120400 is an apocalyptic number.

31331120400 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31331120400 is an abundant number, since it is smaller than the sum of its proper divisors (77396582970).

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

31331120400 is a wasteful number, since it uses less digits than its factorization.

31331120400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8703113 (or 8703099 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31331120400 its reverse (402113313), we get a palindrome (31733233713).

The spelling of 31331120400 in words is "thirty-one billion, three hundred thirty-one million, one hundred twenty thousand, four hundred".