6438721922 has 16 divisors (see below), whose sum is σ = 9761193144. Its totient is φ = 3185040000.

The previous prime is 6438721903. The next prime is 6438721931. The reversal of 6438721922 is 2291278346.

It can be written as a sum of positive squares in 4 ways, for example, as 6332817241 + 105904681 = 79579^2 + 10291^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 267422 + ... + 290502.

Almost surely, 2^6438721922 is an apocalyptic number.

6438721922 is a deficient number, since it is larger than the sum of its proper divisors (3322471222).

6438721922 is a wasteful number, since it uses less digits than its factorization.

6438721922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24565.

The product of its digits is 290304, while the sum is 44.

The square root of 6438721922 is about 80241.6470543819. The cubic root of 6438721922 is about 1860.3724079923.

The spelling of 6438721922 in words is "six billion, four hundred thirty-eight million, seven hundred twenty-one thousand, nine hundred twenty-two".