66777081 has 16 divisors (see below), whose sum is σ = 102159744. Its totient is φ = 38006784.

The previous prime is 66777047. The next prime is 66777089. The reversal of 66777081 is 18077766.

It is not a de Polignac number, because 66777081 - 2⁶ = 66777017 is a prime.

It is a super-2 number, since 2×66777081² = 8918357093761122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66777089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 790 + ... + 11583.

It is an arithmetic number, because the mean of its divisors is an integer number (6384984).

Almost surely, 2^66777081 is an apocalyptic number.

It is an amenable number.

66777081 is a deficient number, since it is larger than the sum of its proper divisors (35382663).

66777081 is a wasteful number, since it uses less digits than its factorization.

66777081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12640.

The product of its (nonzero) digits is 98784, while the sum is 42.

The square root of 66777081 is about 8171.7244814054. The cubic root of 66777081 is about 405.7038636612.

The spelling of 66777081 in words is "sixty-six million, seven hundred seventy-seven thousand, eighty-one".