66616864 has 12 divisors (see below), whose sum is σ = 131152014. Its totient is φ = 33308416.

The previous prime is 66616859. The next prime is 66616871. The reversal of 66616864 is 46861666.

It can be written as a sum of positive squares in only one way, i.e., 62536464 + 4080400 = 7908^2 + 2020^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66616864.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1040857 + ... + 1040920.

Almost surely, 2^66616864 is an apocalyptic number.

It is an amenable number.

66616864 is a deficient number, since it is larger than the sum of its proper divisors (64535150).

66616864 is a wasteful number, since it uses less digits than its factorization.

66616864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2081787 (or 2081779 counting only the distinct ones).

The product of its digits is 248832, while the sum is 43.

The square root of 66616864 is about 8161.9154614588. The cubic root of 66616864 is about 405.3791379254.

The spelling of 66616864 in words is "sixty-six million, six hundred sixteen thousand, eight hundred sixty-four".