631688320511 has 4 divisors (see below), whose sum is σ = 635871687024. Its totient is φ = 627504954000.

The previous prime is 631688320493. The next prime is 631688320567. The reversal of 631688320511 is 115023886136.

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 631688320511 - 2¹⁸ = 631688058367 is a prime.

It is a super-2 number, since 2×631688320511² (a number of 24 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 (631618320511) 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, 2091683030 + ... + 2091683331.

It is an arithmetic number, because the mean of its divisors is an integer number (158967921756).

Almost surely, 2^631688320511 is an apocalyptic number.

631688320511 is a deficient number, since it is larger than the sum of its proper divisors (4183366513).

631688320511 is a wasteful number, since it uses less digits than its factorization.

631688320511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4183366512.

The product of its (nonzero) digits is 207360, while the sum is 44.

The spelling of 631688320511 in words is "six hundred thirty-one billion, six hundred eighty-eight million, three hundred twenty thousand, five hundred eleven".