666720752 has 20 divisors (see below), whose sum is σ = 1311053736. Its totient is φ = 328384320.

The previous prime is 666720749. The next prime is 666720779. The reversal of 666720752 is 257027666.

It is a happy number.

It is a super-2 number, since 2×666720752² = 889033122294891008, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 309899 + ... + 312042.

Almost surely, 2^666720752 is an apocalyptic number.

It is an amenable number.

666720752 is a deficient number, since it is larger than the sum of its proper divisors (644332984).

666720752 is a wasteful number, since it uses less digits than its factorization.

666720752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622016 (or 622010 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 41.

The square root of 666720752 is about 25820.9363114508. The cubic root of 666720752 is about 873.6040880428.

The spelling of 666720752 in words is "six hundred sixty-six million, seven hundred twenty thousand, seven hundred fifty-two".