138195923 has 4 divisors (see below), whose sum is σ = 142653888. Its totient is φ = 133737960.

The previous prime is 138195917. The next prime is 138195929. The reversal of 138195923 is 329591831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 329591831 = 89 ⋅3703279.

It is an interprime number because it is at equal distance from previous prime (138195917) and next prime (138195929).

It is a cyclic number.

It is not a de Polignac number, because 138195923 - 2⁶ = 138195859 is a prime.

It is a super-2 number, since 2×138195923² = 38196226267643858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138195929) 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, 2228936 + ... + 2228997.

It is an arithmetic number, because the mean of its divisors is an integer number (35663472).

Almost surely, 2^138195923 is an apocalyptic number.

138195923 is a deficient number, since it is larger than the sum of its proper divisors (4457965).

138195923 is an equidigital number, since it uses as much as digits as its factorization.

138195923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4457964.

The product of its digits is 58320, while the sum is 41.

The square root of 138195923 is about 11755.6762034347. The cubic root of 138195923 is about 517.0093654733.

The spelling of 138195923 in words is "one hundred thirty-eight million, one hundred ninety-five thousand, nine hundred twenty-three".