66779557359376 has 15 divisors (see below), whose sum is σ = 129385455715861. Its totient is φ = 33389762335936.

The previous prime is 66779557359371. The next prime is 66779557359391. The reversal of 66779557359376 is 67395375597766.

The square root of 66779557359376 is 8171876.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 63350838536976 + 3428718822400 = 7959324^2 + 1851680^2 .

It is a super-2 number, since 2×66779557359376² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66779557359293 and 66779557359302.

It is not an unprimeable number, because it can be changed into a prime (66779557359371) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 31666020 + ... + 33708988.

Almost surely, 2^{66779557359376} is an apocalyptic number.

66779557359376 is the 8171876-th square number.

It is an amenable number.

66779557359376 is a deficient number, since it is larger than the sum of its proper divisors (62605898356485).

66779557359376 is an frugal number, since it uses more digits than its factorization.

66779557359376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4085946 (or 2042971 counting only the distinct ones).

The product of its digits is 47258883000, while the sum is 85.

The spelling of 66779557359376 in words is "sixty-six trillion, seven hundred seventy-nine billion, five hundred fifty-seven million, three hundred fifty-nine thousand, three hundred seventy-six".