138688313 has 4 divisors (see below), whose sum is σ = 138746868. Its totient is φ = 138629760.

The previous prime is 138688309. The next prime is 138688331. The reversal of 138688313 is 313886831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 313886831 = 347 ⋅904573.

It can be written as a sum of positive squares in 2 ways, for example, as 53993104 + 84695209 = 7348^2 + 9203^2 .

It is a cyclic number.

It is not a de Polignac number, because 138688313 - 2² = 138688309 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138688343) 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, 25568 + ... + 30513.

It is an arithmetic number, because the mean of its divisors is an integer number (34686717).

Almost surely, 2^138688313 is an apocalyptic number.

It is an amenable number.

138688313 is a deficient number, since it is larger than the sum of its proper divisors (58555).

138688313 is an equidigital number, since it uses as much as digits as its factorization.

138688313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58554.

The product of its digits is 82944, while the sum is 41.

The square root of 138688313 is about 11776.6002309665. The cubic root of 138688313 is about 517.6226698547.

The spelling of 138688313 in words is "one hundred thirty-eight million, six hundred eighty-eight thousand, three hundred thirteen".