666640750 has 32 divisors (see below), whose sum is σ = 1255007520. Its totient is φ = 265148800.

The previous prime is 666640697. The next prime is 666640753. The reversal of 666640750 is 57046666.

666640750 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666640753) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37302 + ... + 52198.

It is an arithmetic number, because the mean of its divisors is an integer number (39218985).

Almost surely, 2^666640750 is an apocalyptic number.

666640750 is a deficient number, since it is larger than the sum of its proper divisors (588366770).

666640750 is a wasteful number, since it uses less digits than its factorization.

666640750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15093 (or 15083 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 666640750 is about 25819.3870957465. The cubic root of 666640750 is about 873.5691444427.

The spelling of 666640750 in words is "six hundred sixty-six million, six hundred forty thousand, seven hundred fifty".