66177816356 has 6 divisors (see below), whose sum is σ = 115811178630. Its totient is φ = 33088908176.

The previous prime is 66177816337. The next prime is 66177816407. The reversal of 66177816356 is 65361877166.

It can be written as a sum of positive squares in only one way, i.e., 51297720100 + 14880096256 = 226490^2 + 121984^2 .

It is a super-2 number, since 2×66177816356² (a number of 22 digits) 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, 8272227041 + ... + 8272227048.

It is an arithmetic number, because the mean of its divisors is an integer number (19301863105).

Almost surely, 2^66177816356 is an apocalyptic number.

It is an amenable number.

66177816356 is a deficient number, since it is larger than the sum of its proper divisors (49633362274).

66177816356 is a wasteful number, since it uses less digits than its factorization.

66177816356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16544454093 (or 16544454091 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 56.

The spelling of 66177816356 in words is "sixty-six billion, one hundred seventy-seven million, eight hundred sixteen thousand, three hundred fifty-six".