138925391 has 4 divisors (see below), whose sum is σ = 151554984. Its totient is φ = 126295800.

The previous prime is 138925379. The next prime is 138925393. The reversal of 138925391 is 193529831.

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 138925391 - 2¹⁴ = 138909007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138925393) 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, 6314780 + ... + 6314801.

It is an arithmetic number, because the mean of its divisors is an integer number (37888746).

Almost surely, 2^138925391 is an apocalyptic number.

138925391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138925391 is a deficient number, since it is larger than the sum of its proper divisors (12629593).

138925391 is a wasteful number, since it uses less digits than its factorization.

138925391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12629592.

The product of its digits is 58320, while the sum is 41.

The square root of 138925391 is about 11786.6615714544. The cubic root of 138925391 is about 517.9174485702.

It can be divided in two parts, 138 and 925391, that added together give a palindrome (925529).

The spelling of 138925391 in words is "one hundred thirty-eight million, nine hundred twenty-five thousand, three hundred ninety-one".