318873666721 has 27 divisors (see below), whose sum is σ = 345185996371. Its totient is φ = 294505642304.

The previous prime is 318873666707. The next prime is 318873666743. The reversal of 318873666721 is 127666378813.

The square root of 318873666721 is 564689.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 248258045025 + 70615621696 = 498255^2 + 265736^2 .

It is not a de Polignac number, because 318873666721 - 2⁵ = 318873666689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (318873666701) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 566382786 + ... + 566383348.

Almost surely, 2^318873666721 is an apocalyptic number.

318873666721 is the 564689-th square number.

318873666721 is the 282345-th centered octagonal number.

It is an amenable number.

318873666721 is a deficient number, since it is larger than the sum of its proper divisors (26312329650).

318873666721 is an frugal number, since it uses more digits than its factorization.

318873666721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1278 (or 639 counting only the distinct ones).

The product of its digits is 12192768, while the sum is 58.

The spelling of 318873666721 in words is "three hundred eighteen billion, eight hundred seventy-three million, six hundred sixty-six thousand, seven hundred twenty-one".