138481407 has 20 divisors (see below), whose sum is σ = 210266056. Its totient is φ = 90804240.

The previous prime is 138481397. The next prime is 138481423. The reversal of 138481407 is 704184831.

138481407 is a `hidden beast` number, since 138 + 481 + 40 + 7 = 666.

138481407 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 138481407 - 2⁸ = 138481151 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 (138481487) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9073 + ... + 18954.

Almost surely, 2^138481407 is an apocalyptic number.

138481407 is a deficient number, since it is larger than the sum of its proper divisors (71784649).

138481407 is an equidigital number, since it uses as much as digits as its factorization.

138481407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28100 (or 28091 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 138481407 is about 11767.8123285511. The cubic root of 138481407 is about 517.3651318361.

The spelling of 138481407 in words is "one hundred thirty-eight million, four hundred eighty-one thousand, four hundred seven".