66745988 has 6 divisors (see below), whose sum is σ = 116805486. Its totient is φ = 33372992.

The previous prime is 66745979. The next prime is 66745997. The reversal of 66745988 is 88954766.

It is an interprime number because it is at equal distance from previous prime (66745979) and next prime (66745997).

It can be written as a sum of positive squares in only one way, i.e., 64128064 + 2617924 = 8008^2 + 1618^2 .

It is a super-2 number, since 2×66745988² = 8910053828192288, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8343245 + ... + 8343252.

It is an arithmetic number, because the mean of its divisors is an integer number (19467581).

Almost surely, 2^66745988 is an apocalyptic number.

It is an amenable number.

66745988 is a deficient number, since it is larger than the sum of its proper divisors (50059498).

66745988 is a wasteful number, since it uses less digits than its factorization.

66745988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16686501 (or 16686499 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 53.

The square root of 66745988 is about 8169.8217850820. The cubic root of 66745988 is about 405.6408854236.

The spelling of 66745988 in words is "sixty-six million, seven hundred forty-five thousand, nine hundred eighty-eight".