723512138 has 4 divisors (see below), whose sum is σ = 1085268210. Its totient is φ = 361756068.

The previous prime is 723512113. The next prime is 723512143. The reversal of 723512138 is 831215327.

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

It can be written as a sum of positive squares in only one way, i.e., 594530689 + 128981449 = 24383^2 + 11357^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 180878033 + ... + 180878036.

Almost surely, 2^723512138 is an apocalyptic number.

723512138 is a deficient number, since it is larger than the sum of its proper divisors (361756072).

723512138 is a wasteful number, since it uses less digits than its factorization.

723512138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361756071.

The product of its digits is 10080, while the sum is 32.

The square root of 723512138 is about 26898.1809422124. The cubic root of 723512138 is about 897.7359297811.

The spelling of 723512138 in words is "seven hundred twenty-three million, five hundred twelve thousand, one hundred thirty-eight".