138157923 has 8 divisors (see below), whose sum is σ = 184483008. Its totient is φ = 91969064.

The previous prime is 138157907. The next prime is 138157933. The reversal of 138157923 is 329751831.

138157923 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138157923 - 2⁴ = 138157907 is a prime.

It is a super-2 number, since 2×138157923² = 38175223375347858, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138157933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31665 + ... + 35762.

It is an arithmetic number, because the mean of its divisors is an integer number (23060376).

Almost surely, 2^138157923 is an apocalyptic number.

138157923 is a deficient number, since it is larger than the sum of its proper divisors (46325085).

138157923 is an equidigital number, since it uses as much as digits as its factorization.

138157923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68113.

The product of its digits is 45360, while the sum is 39.

The square root of 138157923 is about 11754.0598518129. The cubic root of 138157923 is about 516.9619734411.

The spelling of 138157923 in words is "one hundred thirty-eight million, one hundred fifty-seven thousand, nine hundred twenty-three".