138278450 has 18 divisors (see below), whose sum is σ = 257352669. Its totient is φ = 55278120.

The previous prime is 138278449. The next prime is 138278471. The reversal of 138278450 is 54872831.

It can be written as a sum of positive squares in 2 ways, for example, as 135512881 + 2765569 = 11641^2 + 1663^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=8315.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 82319 + ... + 83981.

Almost surely, 2^138278450 is an apocalyptic number.

138278450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138278450 is a deficient number, since it is larger than the sum of its proper divisors (119074219).

138278450 is an frugal number, since it uses more digits than its factorization.

138278450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3338 (or 1670 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 38.

The square root of 138278450 is about 11759.1857711323. The cubic root of 138278450 is about 517.1122598292.

The spelling of 138278450 in words is "one hundred thirty-eight million, two hundred seventy-eight thousand, four hundred fifty".