138438407 has 4 divisors (see below), whose sum is σ = 138504120. Its totient is φ = 138372696.

The previous prime is 138438397. The next prime is 138438409. The reversal of 138438407 is 704834831.

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 138438407 - 2⁸ = 138438151 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 (138438409) 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, 29588 + ... + 33945.

It is an arithmetic number, because the mean of its divisors is an integer number (34626030).

Almost surely, 2^138438407 is an apocalyptic number.

138438407 is a deficient number, since it is larger than the sum of its proper divisors (65713).

138438407 is an equidigital number, since it uses as much as digits as its factorization.

138438407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65712.

The product of its (nonzero) digits is 64512, while the sum is 38.

The square root of 138438407 is about 11765.9851691220. The cubic root of 138438407 is about 517.3115771047.

The spelling of 138438407 in words is "one hundred thirty-eight million, four hundred thirty-eight thousand, four hundred seven".