138403919 has 4 divisors (see below), whose sum is σ = 146545344. Its totient is φ = 130262496.

The previous prime is 138403913. The next prime is 138403927. The reversal of 138403919 is 919304831.

It is a happy number.

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 138403919 - 2²⁰ = 137355343 is a prime.

It is a super-2 number, since 2×138403919² = 38311289589117122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138403913) 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, 4070687 + ... + 4070720.

It is an arithmetic number, because the mean of its divisors is an integer number (36636336).

Almost surely, 2^138403919 is an apocalyptic number.

138403919 is a deficient number, since it is larger than the sum of its proper divisors (8141425).

138403919 is an equidigital number, since it uses as much as digits as its factorization.

138403919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8141424.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 138403919 is about 11764.5194972000. The cubic root of 138403919 is about 517.2686157045.

The spelling of 138403919 in words is "one hundred thirty-eight million, four hundred three thousand, nine hundred nineteen".