669728831 has 2 divisors, whose sum is σ = 669728832. Its totient is φ = 669728830.

The previous prime is 669728797. The next prime is 669728833. The reversal of 669728831 is 138827966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 669728831 - 2⁶ = 669728767 is a prime.

It is a super-2 number, since 2×669728831² = 897073414145253122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 669728833, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 669728831.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669728833) 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 as a sum of consecutive naturals, namely, 334864415 + 334864416.

It is an arithmetic number, because the mean of its divisors is an integer number (334864416).

Almost surely, 2^669728831 is an apocalyptic number.

669728831 is a deficient number, since it is larger than the sum of its proper divisors (1).

669728831 is an equidigital number, since it uses as much as digits as its factorization.

669728831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 50.

The square root of 669728831 is about 25879.1195947621. The cubic root of 669728831 is about 874.9159455585.

The spelling of 669728831 in words is "six hundred sixty-nine million, seven hundred twenty-eight thousand, eight hundred thirty-one".