722417638 has 4 divisors (see below), whose sum is σ = 1083626460. Its totient is φ = 361208818.

The previous prime is 722417623. The next prime is 722417671. The reversal of 722417638 is 836714227.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 722417638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 180604408 + ... + 180604411.

It is an arithmetic number, because the mean of its divisors is an integer number (270906615).

Almost surely, 2^722417638 is an apocalyptic number.

722417638 is a deficient number, since it is larger than the sum of its proper divisors (361208822).

722417638 is a wasteful number, since it uses less digits than its factorization.

722417638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361208821.

The product of its digits is 112896, while the sum is 40.

The square root of 722417638 is about 26877.8280000449. The cubic root of 722417638 is about 897.2830150772.

The spelling of 722417638 in words is "seven hundred twenty-two million, four hundred seventeen thousand, six hundred thirty-eight".