668127631 has 2 divisors, whose sum is σ = 668127632. Its totient is φ = 668127630.

The previous prime is 668127587. The next prime is 668127643. The reversal of 668127631 is 136721866.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 668127631 - 2⁷ = 668127503 is a prime.

It is a super-3 number, since 3×668127631³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668127661) 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, 334063815 + 334063816.

It is an arithmetic number, because the mean of its divisors is an integer number (334063816).

Almost surely, 2^668127631 is an apocalyptic number.

668127631 is a deficient number, since it is larger than the sum of its proper divisors (1).

668127631 is an equidigital number, since it uses as much as digits as its factorization.

668127631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 40.

The square root of 668127631 is about 25848.1649445372. The cubic root of 668127631 is about 874.2181341074.

The spelling of 668127631 in words is "six hundred sixty-eight million, one hundred twenty-seven thousand, six hundred thirty-one".