639617654 has 32 divisors (see below), whose sum is σ = 1054408320. Its totient is φ = 289216512.

The previous prime is 639617617. The next prime is 639617663. The reversal of 639617654 is 456716936.

It is a super-2 number, since 2×639617654² = 818221486616927432, which contains 22 as substring.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 639617599 and 639617608.

It is a congruent number.

It is an unprimeable number.

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, 280262 + ... + 282534.

It is an arithmetic number, because the mean of its divisors is an integer number (32950260).

Almost surely, 2^639617654 is an apocalyptic number.

639617654 is a deficient number, since it is larger than the sum of its proper divisors (414790666).

639617654 is a wasteful number, since it uses less digits than its factorization.

639617654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2504.

The product of its digits is 816480, while the sum is 47.

The square root of 639617654 is about 25290.6633760366. The cubic root of 639617654 is about 861.6022294338.

The spelling of 639617654 in words is "six hundred thirty-nine million, six hundred seventeen thousand, six hundred fifty-four".