66662731 has 2 divisors, whose sum is σ = 66662732. Its totient is φ = 66662730.

The previous prime is 66662723. The next prime is 66662753. The reversal of 66662731 is 13726666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66662731 - 2³ = 66662723 is a prime.

It is a super-2 number, since 2×66662731² = 8887839408756722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66662231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33331365 + 33331366.

It is an arithmetic number, because the mean of its divisors is an integer number (33331366).

Almost surely, 2^66662731 is an apocalyptic number.

66662731 is a deficient number, since it is larger than the sum of its proper divisors (1).

66662731 is an equidigital number, since it uses as much as digits as its factorization.

66662731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 37.

The square root of 66662731 is about 8164.7247963419. The cubic root of 66662731 is about 405.4721537080.

The spelling of 66662731 in words is "sixty-six million, six hundred sixty-two thousand, seven hundred thirty-one".