668472660 has 36 divisors (see below), whose sum is σ = 2027700948. Its totient is φ = 178259328.

The previous prime is 668472659. The next prime is 668472661. The reversal of 668472660 is 66274866.

It is an interprime number because it is at equal distance from previous prime (668472659) and next prime (668472661).

It can be written as a sum of positive squares in 2 ways, for example, as 73307844 + 595164816 = 8562^2 + 24396^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668472661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1856689 + ... + 1857048.

Almost surely, 2^668472660 is an apocalyptic number.

668472660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668472660 is an abundant number, since it is smaller than the sum of its proper divisors (1359228288).

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

668472660 is a wasteful number, since it uses less digits than its factorization.

668472660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3713752 (or 3713747 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The square root of 668472660 is about 25854.8382319441. The cubic root of 668472660 is about 874.3685937340.

The spelling of 668472660 in words is "six hundred sixty-eight million, four hundred seventy-two thousand, six hundred sixty".