138361391 has 4 divisors (see below), whose sum is σ = 158127312. Its totient is φ = 118595472.

The previous prime is 138361387. The next prime is 138361393. The reversal of 138361391 is 193163831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138361391 - 2² = 138361387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138361393) 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, 9882950 + ... + 9882963.

It is an arithmetic number, because the mean of its divisors is an integer number (39531828).

Almost surely, 2^138361391 is an apocalyptic number.

138361391 is a deficient number, since it is larger than the sum of its proper divisors (19765921).

138361391 is an equidigital number, since it uses as much as digits as its factorization.

138361391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19765920.

The product of its digits is 11664, while the sum is 35.

The square root of 138361391 is about 11762.7118896962. The cubic root of 138361391 is about 517.2156291191.

The spelling of 138361391 in words is "one hundred thirty-eight million, three hundred sixty-one thousand, three hundred ninety-one".