138868331 has 4 divisors (see below), whose sum is σ = 158706672. Its totient is φ = 119029992.

The previous prime is 138868309. The next prime is 138868337. The reversal of 138868331 is 133868831.

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

It is a cyclic number.

It is not a de Polignac number, because 138868331 - 2¹⁸ = 138606187 is a prime.

It is a super-2 number, since 2×138868331² = 38568826709451122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138868337) 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, 9919160 + ... + 9919173.

It is an arithmetic number, because the mean of its divisors is an integer number (39676668).

Almost surely, 2^138868331 is an apocalyptic number.

138868331 is a deficient number, since it is larger than the sum of its proper divisors (19838341).

138868331 is an equidigital number, since it uses as much as digits as its factorization.

138868331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19838340.

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

The square root of 138868331 is about 11784.2407901400. The cubic root of 138868331 is about 517.8465318086.

The spelling of 138868331 in words is "one hundred thirty-eight million, eight hundred sixty-eight thousand, three hundred thirty-one".