31218628761 has 12 divisors (see below), whose sum is σ = 45766614192. Its totient is φ = 20501785656.

The previous prime is 31218628741. The next prime is 31218628783. The reversal of 31218628761 is 16782681213.

31218628761 is a `hidden beast` number, since 3 + 1 + 2 + 18 + 628 + 7 + 6 + 1 = 666.

It is not a de Polignac number, because 31218628761 - 2²¹ = 31216531609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31218628741) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 25885491 + ... + 25886696.

It is an arithmetic number, because the mean of its divisors is an integer number (3813884516).

Almost surely, 2^31218628761 is an apocalyptic number.

It is an amenable number.

31218628761 is a deficient number, since it is larger than the sum of its proper divisors (14547985431).

31218628761 is a wasteful number, since it uses less digits than its factorization.

31218628761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51772260 (or 51772257 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The spelling of 31218628761 in words is "thirty-one billion, two hundred eighteen million, six hundred twenty-eight thousand, seven hundred sixty-one".