669624731 has 2 divisors, whose sum is σ = 669624732. Its totient is φ = 669624730.

The previous prime is 669624721. The next prime is 669624757. The reversal of 669624731 is 137426966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 669624731 - 2⁶ = 669624667 is a prime.

It is a super-2 number, since 2×669624731² = 896794560733644722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (669624721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334812365 + 334812366.

It is an arithmetic number, because the mean of its divisors is an integer number (334812366).

Almost surely, 2^669624731 is an apocalyptic number.

669624731 is a deficient number, since it is larger than the sum of its proper divisors (1).

669624731 is an equidigital number, since it uses as much as digits as its factorization.

669624731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 44.

The square root of 669624731 is about 25877.1082426147. The cubic root of 669624731 is about 874.8706120518.

The spelling of 669624731 in words is "six hundred sixty-nine million, six hundred twenty-four thousand, seven hundred thirty-one".