66677731 has 2 divisors, whose sum is σ = 66677732. Its totient is φ = 66677730.

The previous prime is 66677719. The next prime is 66677761. The reversal of 66677731 is 13777666.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66677731 is a prime.

It is a super-2 number, since 2×66677731² = 8891839622616722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66677761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33338865 + 33338866.

It is an arithmetic number, because the mean of its divisors is an integer number (33338866).

Almost surely, 2^66677731 is an apocalyptic number.

66677731 is a deficient number, since it is larger than the sum of its proper divisors (1).

66677731 is an equidigital number, since it uses as much as digits as its factorization.

66677731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 222264, while the sum is 43.

The square root of 66677731 is about 8165.6433304425. The cubic root of 66677731 is about 405.5025636341.

The spelling of 66677731 in words is "sixty-six million, six hundred seventy-seven thousand, seven hundred thirty-one".