722138939 has 4 divisors (see below), whose sum is σ = 735764256. Its totient is φ = 708513624.

The previous prime is 722138933. The next prime is 722138959. The reversal of 722138939 is 939831227.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 939831227 = 4583 ⋅205069.

It is a cyclic number.

It is not a de Polignac number, because 722138939 - 2¹⁶ = 722073403 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 722138939.

It is not an unprimeable number, because it can be changed into a prime (722138933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6812579 + ... + 6812684.

It is an arithmetic number, because the mean of its divisors is an integer number (183941064).

Almost surely, 2^722138939 is an apocalyptic number.

722138939 is a deficient number, since it is larger than the sum of its proper divisors (13625317).

722138939 is a wasteful number, since it uses less digits than its factorization.

722138939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13625316.

The product of its digits is 163296, while the sum is 44.

The square root of 722138939 is about 26872.6429478010. The cubic root of 722138939 is about 897.1676136664.

The spelling of 722138939 in words is "seven hundred twenty-two million, one hundred thirty-eight thousand, nine hundred thirty-nine".