638865663734 has 8 divisors (see below), whose sum is σ = 958312041888. Its totient is φ = 319428316440.

The previous prime is 638865663727. The next prime is 638865663763. The reversal of 638865663734 is 437366568836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2077997 + ... + 2365544.

It is an arithmetic number, because the mean of its divisors is an integer number (119789005236).

Almost surely, 2^638865663734 is an apocalyptic number.

638865663734 is a deficient number, since it is larger than the sum of its proper divisors (319446378154).

638865663734 is a wasteful number, since it uses less digits than its factorization.

638865663734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4515430.

The product of its digits is 313528320, while the sum is 65.

The spelling of 638865663734 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, six hundred sixty-three thousand, seven hundred thirty-four".