138909017025 has 27 divisors (see below), whose sum is σ = 248811497571. Its totient is φ = 74081827440.

The previous prime is 138909016991. The next prime is 138909017041. The reversal of 138909017025 is 520710909831.

The square root of 138909017025 is 372705.

It is a perfect power (a square), and thus also a powerful number.

138909017025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 50007246129 + 88901770896 = 223623^2 + 298164^2 .

It is a de Polignac number, because none of the positive numbers 2^k-138909017025 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 5578152 + ... + 5602998.

Almost surely, 2^138909017025 is an apocalyptic number.

138909017025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138909017025 is the 372705-th square number.

138909017025 is the 186353-rd centered octagonal number.

It is an amenable number.

138909017025 is a deficient number, since it is larger than the sum of its proper divisors (109902480546).

138909017025 is an frugal number, since it uses more digits than its factorization.

138909017025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49710 (or 24855 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The spelling of 138909017025 in words is "one hundred thirty-eight billion, nine hundred nine million, seventeen thousand, twenty-five".