138901409 has 2 divisors, whose sum is σ = 138901410. Its totient is φ = 138901408.

The previous prime is 138901369. The next prime is 138901417. The reversal of 138901409 is 904109831.

138901409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129322384 + 9579025 = 11372^2 + 3095^2 .

It is an emirp because it is prime and its reverse (904109831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138901409 - 2²⁴ = 122124193 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138901459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69450704 + 69450705.

It is an arithmetic number, because the mean of its divisors is an integer number (69450705).

Almost surely, 2^138901409 is an apocalyptic number.

It is an amenable number.

138901409 is a deficient number, since it is larger than the sum of its proper divisors (1).

138901409 is an equidigital number, since it uses as much as digits as its factorization.

138901409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 138901409 is about 11785.6441911336. The cubic root of 138901409 is about 517.8876450166.

The spelling of 138901409 in words is "one hundred thirty-eight million, nine hundred one thousand, four hundred nine".