722128538 has 4 divisors (see below), whose sum is σ = 1083192810. Its totient is φ = 361064268.

The previous prime is 722128529. The next prime is 722128543. The reversal of 722128538 is 835821227.

722128538 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 835821227 = 701 ⋅1192327.

It can be written as a sum of positive squares in only one way, i.e., 708784129 + 13344409 = 26623^2 + 3653^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 180532133 + ... + 180532136.

Almost surely, 2^722128538 is an apocalyptic number.

722128538 is a deficient number, since it is larger than the sum of its proper divisors (361064272).

722128538 is a wasteful number, since it uses less digits than its factorization.

722128538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361064271.

The product of its digits is 53760, while the sum is 38.

The square root of 722128538 is about 26872.4494231546. The cubic root of 722128538 is about 897.1633063304.

The spelling of 722128538 in words is "seven hundred twenty-two million, one hundred twenty-eight thousand, five hundred thirty-eight".