639430902797 has 2 divisors, whose sum is σ = 639430902798. Its totient is φ = 639430902796.

The previous prime is 639430902793. The next prime is 639430902853. The reversal of 639430902797 is 797209034936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 522344434756 + 117086468041 = 722734^2 + 342179^2 .

It is a cyclic number.

It is not a de Polignac number, because 639430902797 - 2² = 639430902793 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639430902793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319715451398 + 319715451399.

It is an arithmetic number, because the mean of its divisors is an integer number (319715451399).

Almost surely, 2^639430902797 is an apocalyptic number.

It is an amenable number.

639430902797 is a deficient number, since it is larger than the sum of its proper divisors (1).

639430902797 is an equidigital number, since it uses as much as digits as its factorization.

639430902797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15431472, while the sum is 59.

The spelling of 639430902797 in words is "six hundred thirty-nine billion, four hundred thirty million, nine hundred two thousand, seven hundred ninety-seven".