66918777 has 8 divisors (see below), whose sum is σ = 89718720. Its totient is φ = 44365680.

The previous prime is 66918757. The next prime is 66918781. The reversal of 66918777 is 77781966.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66918777 - 2⁸ = 66918521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66918727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61077 + ... + 62162.

It is an arithmetic number, because the mean of its divisors is an integer number (11214840).

Almost surely, 2^66918777 is an apocalyptic number.

It is an amenable number.

66918777 is a deficient number, since it is larger than the sum of its proper divisors (22799943).

66918777 is a wasteful number, since it uses less digits than its factorization.

66918777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123423.

The product of its digits is 889056, while the sum is 51.

The square root of 66918777 is about 8180.3897828893. The cubic root of 66918777 is about 405.9906187419.

The spelling of 66918777 in words is "sixty-six million, nine hundred eighteen thousand, seven hundred seventy-seven".