639798633 has 12 divisors (see below), whose sum is σ = 924667380. Its totient is φ = 426295296.

The previous prime is 639798589. The next prime is 639798637. The reversal of 639798633 is 336897936.

It can be written as a sum of positive squares in 2 ways, for example, as 231435369 + 408363264 = 15213^2 + 20208^2 .

It is not a de Polignac number, because 639798633 - 2¹² = 639794537 is a prime.

It is a super-4 number, since 4×639798633⁴ (a number of 36 digits) contains 4444 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 639798633.

It is not an unprimeable number, because it can be changed into a prime (639798637) 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 in 11 ways as a sum of consecutive naturals, for example, 1816 + ... + 35817.

It is an arithmetic number, because the mean of its divisors is an integer number (77055615).

Almost surely, 2^639798633 is an apocalyptic number.

It is an amenable number.

639798633 is a deficient number, since it is larger than the sum of its proper divisors (284868747).

639798633 is a wasteful number, since it uses less digits than its factorization.

639798633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39528 (or 39525 counting only the distinct ones).

The product of its digits is 4408992, while the sum is 54.

The square root of 639798633 is about 25294.2411034607. The cubic root of 639798633 is about 861.6834848549.

The spelling of 639798633 in words is "six hundred thirty-nine million, seven hundred ninety-eight thousand, six hundred thirty-three".