639997941 has 16 divisors (see below), whose sum is σ = 936488448. Its totient is φ = 385551600.

The previous prime is 639997937. The next prime is 639997951. The reversal of 639997941 is 149799936.

It is not a de Polignac number, because 639997941 - 2² = 639997937 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639997901) 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 in 15 ways as a sum of consecutive naturals, for example, 52555 + ... + 63576.

It is an arithmetic number, because the mean of its divisors is an integer number (58530528).

Almost surely, 2^639997941 is an apocalyptic number.

It is an amenable number.

639997941 is a deficient number, since it is larger than the sum of its proper divisors (296490507).

639997941 is a wasteful number, since it uses less digits than its factorization.

639997941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116312.

The product of its digits is 3306744, while the sum is 57.

The square root of 639997941 is about 25298.1805867537. The cubic root of 639997941 is about 861.7729518490.

The spelling of 639997941 in words is "six hundred thirty-nine million, nine hundred ninety-seven thousand, nine hundred forty-one".