318861845721 has 48 divisors (see below), whose sum is σ = 479468740608. Its totient is φ = 203974898400.

The previous prime is 318861845719. The next prime is 318861845759. The reversal of 318861845721 is 127548168813.

318861845721 is a `hidden beast` number, since 3 + 1 + 8 + 8 + 61 + 8 + 4 + 572 + 1 = 666.

It is not a de Polignac number, because 318861845721 - 2¹ = 318861845719 is a prime.

It is a super-3 number, since 3×318861845721³ (a number of 35 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (318861845791) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 54345430 + ... + 54351296.

It is an arithmetic number, because the mean of its divisors is an integer number (9988932096).

Almost surely, 2^318861845721 is an apocalyptic number.

318861845721 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

318861845721 is a deficient number, since it is larger than the sum of its proper divisors (160606894887).

318861845721 is a wasteful number, since it uses less digits than its factorization.

318861845721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7522 (or 7519 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 54.

The spelling of 318861845721 in words is "three hundred eighteen billion, eight hundred sixty-one million, eight hundred forty-five thousand, seven hundred twenty-one".