138293231 has 4 divisors (see below), whose sum is σ = 139057464. Its totient is φ = 137529000.

The previous prime is 138293173. The next prime is 138293237. The reversal of 138293231 is 132392831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 132392831 = 317 ⋅417643.

It is a cyclic number.

It is not a de Polignac number, because 138293231 - 2¹⁴ = 138276847 is a prime.

It is a super-2 number, since 2×138293231² = 38250035480838722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138293237) 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, 381845 + ... + 382206.

It is an arithmetic number, because the mean of its divisors is an integer number (34764366).

Almost surely, 2^138293231 is an apocalyptic number.

138293231 is a deficient number, since it is larger than the sum of its proper divisors (764233).

138293231 is an equidigital number, since it uses as much as digits as its factorization.

138293231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764232.

The product of its digits is 7776, while the sum is 32.

The square root of 138293231 is about 11759.8142417302. The cubic root of 138293231 is about 517.1306844017.

The spelling of 138293231 in words is "one hundred thirty-eight million, two hundred ninety-three thousand, two hundred thirty-one".