138473421 has 12 divisors (see below), whose sum is σ = 188750016. Its totient is φ = 90260280.

The previous prime is 138473407. The next prime is 138473429. The reversal of 138473421 is 124374831.

138473421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138473421 - 2⁹ = 138472909 is a prime.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138473429) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 139236 + ... + 140226.

It is an arithmetic number, because the mean of its divisors is an integer number (15729168).

Almost surely, 2^138473421 is an apocalyptic number.

It is an amenable number.

138473421 is a deficient number, since it is larger than the sum of its proper divisors (50276595).

138473421 is an frugal number, since it uses more digits than its factorization.

138473421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2032 (or 1041 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 138473421 is about 11767.4730082546. The cubic root of 138473421 is about 517.3551864400.

The spelling of 138473421 in words is "one hundred thirty-eight million, four hundred seventy-three thousand, four hundred twenty-one".