138481551 has 24 divisors (see below), whose sum is σ = 224786016. Its totient is φ = 81512640.

The previous prime is 138481531. The next prime is 138481573. The reversal of 138481551 is 155184831.

It is not a de Polignac number, because 138481551 - 2⁶ = 138481487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138481501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23040 + ... + 28421.

It is an arithmetic number, because the mean of its divisors is an integer number (9366084).

Almost surely, 2^138481551 is an apocalyptic number.

138481551 is a deficient number, since it is larger than the sum of its proper divisors (86304465).

138481551 is a wasteful number, since it uses less digits than its factorization.

138481551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51503 (or 51500 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

The square root of 138481551 is about 11767.8184469340. The cubic root of 138481551 is about 517.3653111636.

The spelling of 138481551 in words is "one hundred thirty-eight million, four hundred eighty-one thousand, five hundred fifty-one".