638660463663 has 8 divisors (see below), whose sum is σ = 851637614976. Its totient is φ = 425728477400.

The previous prime is 638660463613. The next prime is 638660463667. The reversal of 638660463663 is 366364066836.

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

It is a cyclic number.

It is not a de Polignac number, because 638660463663 - 2⁹ = 638660463151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638660463667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11258253 + ... + 11314838.

It is an arithmetic number, because the mean of its divisors is an integer number (106454701872).

Almost surely, 2^638660463663 is an apocalyptic number.

638660463663 is a deficient number, since it is larger than the sum of its proper divisors (212977151313).

638660463663 is a wasteful number, since it uses less digits than its factorization.

638660463663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22582525.

The product of its (nonzero) digits is 40310784, while the sum is 57.

The spelling of 638660463663 in words is "six hundred thirty-eight billion, six hundred sixty million, four hundred sixty-three thousand, six hundred sixty-three".