638777893 has 16 divisors (see below), whose sum is σ = 707132160. Its totient is φ = 573333696.

The previous prime is 638777863. The next prime is 638777897. The reversal of 638777893 is 398777836.

It is not a de Polignac number, because 638777893 - 2¹³ = 638769701 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 (638777897) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92598 + ... + 99256.

It is an arithmetic number, because the mean of its divisors is an integer number (44195760).

Almost surely, 2^638777893 is an apocalyptic number.

It is an amenable number.

638777893 is a deficient number, since it is larger than the sum of its proper divisors (68354267).

638777893 is a wasteful number, since it uses less digits than its factorization.

638777893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6876.

The product of its digits is 10668672, while the sum is 58.

The square root of 638777893 is about 25274.0557291464. The cubic root of 638777893 is about 861.2249953033.

The spelling of 638777893 in words is "six hundred thirty-eight million, seven hundred seventy-seven thousand, eight hundred ninety-three".