666517968 has 60 divisors (see below), whose sum is σ = 1867082880. Its totient is φ = 221963328.

The previous prime is 666517937. The next prime is 666517981. The reversal of 666517968 is 869715666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 261243 + ... + 263781.

It is an arithmetic number, because the mean of its divisors is an integer number (31118048).

Almost surely, 2^666517968 is an apocalyptic number.

It is an amenable number.

666517968 is an abundant number, since it is smaller than the sum of its proper divisors (1200564912).

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

666517968 is a wasteful number, since it uses less digits than its factorization.

666517968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4376 (or 4367 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The square root of 666517968 is about 25817.0092768314. The cubic root of 666517968 is about 873.5155097815.

The spelling of 666517968 in words is "six hundred sixty-six million, five hundred seventeen thousand, nine hundred sixty-eight".