638468000405 has 16 divisors (see below), whose sum is σ = 792604969200. Its totient is φ = 493146554880.

The previous prime is 638468000399. The next prime is 638468000477. The reversal of 638468000405 is 504000864836.

It can be written as a sum of positive squares in 8 ways, for example, as 16100056996 + 622367943409 = 126886^2 + 788903^2 .

It is not a de Polignac number, because 638468000405 - 2¹⁰ = 638467999381 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8687915 + ... + 8761095.

It is an arithmetic number, because the mean of its divisors is an integer number (49537810575).

Almost surely, 2^638468000405 is an apocalyptic number.

It is an amenable number.

638468000405 is a deficient number, since it is larger than the sum of its proper divisors (154136968795).

638468000405 is a wasteful number, since it uses less digits than its factorization.

638468000405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133384.

The product of its (nonzero) digits is 552960, while the sum is 44.

The spelling of 638468000405 in words is "six hundred thirty-eight billion, four hundred sixty-eight million, four hundred five", and thus it is an aban number.