31218112880639 has 4 divisors (see below), whose sum is σ = 31264225308024. Its totient is φ = 31172000453256.

The previous prime is 31218112880627. The next prime is 31218112880657. The reversal of 31218112880639 is 93608821181213.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31218112880639 - 2³⁶ = 31149393403903 is a prime.

It is a super-2 number, since 2×31218112880639² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31218112880839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23056212677 + ... + 23056214030.

It is an arithmetic number, because the mean of its divisors is an integer number (7816056327006).

Almost surely, 2^{31218112880639} is an apocalyptic number.

31218112880639 is a deficient number, since it is larger than the sum of its proper divisors (46112427385).

31218112880639 is an equidigital number, since it uses as much as digits as its factorization.

31218112880639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46112427384.

The product of its (nonzero) digits is 995328, while the sum is 53.

The spelling of 31218112880639 in words is "thirty-one trillion, two hundred eighteen billion, one hundred twelve million, eight hundred eighty thousand, six hundred thirty-nine".