320816138 has 4 divisors (see below), whose sum is σ = 481224210. Its totient is φ = 160408068.

The previous prime is 320816131. The next prime is 320816147. The reversal of 320816138 is 831618023.

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: 831618023 = 1091 ⋅762253.

It can be written as a sum of positive squares in only one way, i.e., 300086329 + 20729809 = 17323^2 + 4553^2 .

It is not an unprimeable number, because it can be changed into a prime (320816131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80204033 + ... + 80204036.

Almost surely, 2^320816138 is an apocalyptic number.

320816138 is a deficient number, since it is larger than the sum of its proper divisors (160408072).

320816138 is a wasteful number, since it uses less digits than its factorization.

320816138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160408071.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 320816138 is about 17911.3410441541. The cubic root of 320816138 is about 684.5713751652.

The spelling of 320816138 in words is "three hundred twenty million, eight hundred sixteen thousand, one hundred thirty-eight".