639349793 has 2 divisors, whose sum is σ = 639349794. Its totient is φ = 639349792.

The previous prime is 639349693. The next prime is 639349801. The reversal of 639349793 is 397943936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 638471824 + 877969 = 25268^2 + 937^2 .

It is a cyclic number.

It is not a de Polignac number, because 639349793 - 2⁸ = 639349537 is a prime.

It is not a weakly prime, because it can be changed into another prime (639349393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319674896 + 319674897.

It is an arithmetic number, because the mean of its divisors is an integer number (319674897).

Almost surely, 2^639349793 is an apocalyptic number.

It is an amenable number.

639349793 is a deficient number, since it is larger than the sum of its proper divisors (1).

639349793 is an equidigital number, since it uses as much as digits as its factorization.

639349793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3306744, while the sum is 53.

The square root of 639349793 is about 25285.3671715481. The cubic root of 639349793 is about 861.4819378514.

The spelling of 639349793 in words is "six hundred thirty-nine million, three hundred forty-nine thousand, seven hundred ninety-three".