666737431 has 2 divisors, whose sum is σ = 666737432. Its totient is φ = 666737430.

The previous prime is 666737389. The next prime is 666737459. The reversal of 666737431 is 134737666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666737431 is a prime.

It is a super-2 number, since 2×666737431² = 889077603792959522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666737471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333368715 + 333368716.

It is an arithmetic number, because the mean of its divisors is an integer number (333368716).

Almost surely, 2^666737431 is an apocalyptic number.

666737431 is a deficient number, since it is larger than the sum of its proper divisors (1).

666737431 is an equidigital number, since it uses as much as digits as its factorization.

666737431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 381024, while the sum is 43.

The square root of 666737431 is about 25821.2592837762. The cubic root of 666737431 is about 873.6113728123.

The spelling of 666737431 in words is "six hundred sixty-six million, seven hundred thirty-seven thousand, four hundred thirty-one".