668644480 has 64 divisors (see below), whose sum is σ = 1826844480. Its totient is φ = 229248000.

The previous prime is 668644421. The next prime is 668644489. The reversal of 668644480 is 84446866.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 668644480.

It is not an unprimeable number, because it can be changed into a prime (668644489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70146 + ... + 79105.

It is an arithmetic number, because the mean of its divisors is an integer number (28544445).

Almost surely, 2^668644480 is an apocalyptic number.

It is an amenable number.

668644480 is an abundant number, since it is smaller than the sum of its proper divisors (1158200000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668644480 is a wasteful number, since it uses less digits than its factorization.

668644480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149277 (or 149265 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 46.

The square root of 668644480 is about 25858.1608007994. The cubic root of 668644480 is about 874.4435013809.

It can be divided in two parts, 668644 and 480, that added together give a square (669124 = 818²).

The spelling of 668644480 in words is "six hundred sixty-eight million, six hundred forty-four thousand, four hundred eighty".