666499720 has 32 divisors (see below), whose sum is σ = 1520752320. Its totient is φ = 262843840.

The previous prime is 666499679. The next prime is 666499741. The reversal of 666499720 is 27994666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114502 + ... + 120181.

It is an arithmetic number, because the mean of its divisors is an integer number (47523510).

Almost surely, 2^666499720 is an apocalyptic number.

It is an amenable number.

666499720 is an abundant number, since it is smaller than the sum of its proper divisors (854252600).

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

666499720 is a wasteful number, since it uses less digits than its factorization.

666499720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234765 (or 234761 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 49.

The square root of 666499720 is about 25816.6558639960. The cubic root of 666499720 is about 873.5075379752.

The spelling of 666499720 in words is "six hundred sixty-six million, four hundred ninety-nine thousand, seven hundred twenty".