138905297 has 4 divisors (see below), whose sum is σ = 138984816. Its totient is φ = 138825780.

The previous prime is 138905281. The next prime is 138905339. The reversal of 138905297 is 792509831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 138905297 - 2⁴ = 138905281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138905597) 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, 37079 + ... + 40652.

It is an arithmetic number, because the mean of its divisors is an integer number (34746204).

Almost surely, 2^138905297 is an apocalyptic number.

It is an amenable number.

138905297 is a deficient number, since it is larger than the sum of its proper divisors (79519).

138905297 is an equidigital number, since it uses as much as digits as its factorization.

138905297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79518.

The product of its (nonzero) digits is 136080, while the sum is 44.

The square root of 138905297 is about 11785.8091364149. The cubic root of 138905297 is about 517.8924770491.

The spelling of 138905297 in words is "one hundred thirty-eight million, nine hundred five thousand, two hundred ninety-seven".