138278445 has 32 divisors (see below), whose sum is σ = 233985024. Its totient is φ = 69619200.

The previous prime is 138278429. The next prime is 138278449. The reversal of 138278445 is 544872831.

It is not a de Polignac number, because 138278445 - 2⁴ = 138278429 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138278397 and 138278406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138278449) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15439 + ... + 22691.

It is an arithmetic number, because the mean of its divisors is an integer number (7312032).

Almost surely, 2^138278445 is an apocalyptic number.

138278445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138278445 is a deficient number, since it is larger than the sum of its proper divisors (95706579).

138278445 is a wasteful number, since it uses less digits than its factorization.

138278445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7333.

The product of its digits is 215040, while the sum is 42.

The square root of 138278445 is about 11759.1855585325. The cubic root of 138278445 is about 517.1122535965.

The spelling of 138278445 in words is "one hundred thirty-eight million, two hundred seventy-eight thousand, four hundred forty-five".