31331204120421 has 10 divisors (see below), whose sum is σ = 46803403686182. Its totient is φ = 20887469413560.

The previous prime is 31331204120393. The next prime is 31331204120471. The reversal of 31331204120421 is 12402140213313.

31331204120421 is a `hidden beast` number, since 3 + 1 + 3 + 31 + 204 + 1 + 2 + 0 + 421 = 666.

It can be written as a sum of positive squares in only one way, i.e., 31029021936900 + 302182183521 = 5570370^2 + 549711^2 .

It is a de Polignac number, because none of the positive numbers 2^k-31331204120421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31331204120471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 193402494490 + ... + 193402494651.

Almost surely, 2^{31331204120421} is an apocalyptic number.

It is an amenable number.

31331204120421 is a deficient number, since it is larger than the sum of its proper divisors (15472199565761).

31331204120421 is an equidigital number, since it uses as much as digits as its factorization.

31331204120421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386804989153 (or 386804989144 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

Adding to 31331204120421 its reverse (12402140213313), we get a palindrome (43733344333734).

The spelling of 31331204120421 in words is "thirty-one trillion, three hundred thirty-one billion, two hundred four million, one hundred twenty thousand, four hundred twenty-one".