639862797 has 32 divisors (see below), whose sum is σ = 995180544. Its totient is φ = 358142400.

The previous prime is 639862787. The next prime is 639862801. The reversal of 639862797 is 797268936.

It is a happy number.

It is not a de Polignac number, because 639862797 - 2⁷ = 639862669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639862777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 267547 + ... + 269927.

It is an arithmetic number, because the mean of its divisors is an integer number (31099392).

Almost surely, 2^639862797 is an apocalyptic number.

639862797 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

It is an amenable number.

639862797 is a deficient number, since it is larger than the sum of its proper divisors (355317747).

639862797 is a wasteful number, since it uses less digits than its factorization.

639862797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2649.

The product of its digits is 6858432, while the sum is 57.

The square root of 639862797 is about 25295.5094236111. The cubic root of 639862797 is about 861.7122893402.

The spelling of 639862797 in words is "six hundred thirty-nine million, eight hundred sixty-two thousand, seven hundred ninety-seven".