638323279 has 6 divisors (see below), whose sum is σ = 701628200. Its totient is φ = 580293780.

The previous prime is 638323267. The next prime is 638323313. The reversal of 638323279 is 972323836.

It is not a de Polignac number, because 638323279 - 2⁵ = 638323247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638323249) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2637579 + ... + 2637820.

Almost surely, 2^638323279 is an apocalyptic number.

638323279 is a deficient number, since it is larger than the sum of its proper divisors (63304921).

638323279 is a wasteful number, since it uses less digits than its factorization.

638323279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5275421 (or 5275410 counting only the distinct ones).

The product of its digits is 326592, while the sum is 43.

The square root of 638323279 is about 25265.0604392707. The cubic root of 638323279 is about 861.0206374386.

The spelling of 638323279 in words is "six hundred thirty-eight million, three hundred twenty-three thousand, two hundred seventy-nine".