318688524221 has 4 divisors (see below), whose sum is σ = 318903420192. Its totient is φ = 318473628252.

The previous prime is 318688524211. The next prime is 318688524227. The reversal of 318688524221 is 122425886813.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122425886813 = 19 ⋅6443467727.

It is a cyclic number.

It is not a de Polignac number, because 318688524221 - 2¹⁸ = 318688262077 is a prime.

It is a super-4 number, since 4×318688524221⁴ (a number of 47 digits) contains 4444 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 318688524221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (318688524227) 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, 107445761 + ... + 107448726.

It is an arithmetic number, because the mean of its divisors is an integer number (79725855048).

Almost surely, 2^318688524221 is an apocalyptic number.

It is an amenable number.

318688524221 is a deficient number, since it is larger than the sum of its proper divisors (214895971).

318688524221 is a wasteful number, since it uses less digits than its factorization.

318688524221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214895970.

The product of its digits is 1474560, while the sum is 50.

The spelling of 318688524221 in words is "three hundred eighteen billion, six hundred eighty-eight million, five hundred twenty-four thousand, two hundred twenty-one".