31218738641 has 32 divisors (see below), whose sum is σ = 33829107840. Its totient is φ = 28747547136.

The previous prime is 31218738601. The next prime is 31218738659. The reversal of 31218738641 is 14683781213.

It is a cyclic number.

It is not a de Polignac number, because 31218738641 - 2¹⁰ = 31218737617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31218738592 and 31218738601.

It is not an unprimeable number, because it can be changed into a prime (31218738601) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16318301 + ... + 16320213.

It is an arithmetic number, because the mean of its divisors is an integer number (1057159620).

Almost surely, 2^31218738641 is an apocalyptic number.

It is an amenable number.

31218738641 is a deficient number, since it is larger than the sum of its proper divisors (2610369199).

31218738641 is a wasteful number, since it uses less digits than its factorization.

31218738641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2273.

The product of its digits is 193536, while the sum is 44.

The spelling of 31218738641 in words is "thirty-one billion, two hundred eighteen million, seven hundred thirty-eight thousand, six hundred forty-one".