138297278 has 32 divisors (see below), whose sum is σ = 253886400. Its totient is φ = 55148544.

The previous prime is 138297277. The next prime is 138297283. The reversal of 138297278 is 872792831.

It is a super-2 number, since 2×138297278² = 38252274204418568, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138297277) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17918 + ... + 24446.

It is an arithmetic number, because the mean of its divisors is an integer number (7933950).

Almost surely, 2^138297278 is an apocalyptic number.

138297278 is a deficient number, since it is larger than the sum of its proper divisors (115589122).

138297278 is a wasteful number, since it uses less digits than its factorization.

138297278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6644.

The product of its digits is 338688, while the sum is 47.

The square root of 138297278 is about 11759.9863095158. The cubic root of 138297278 is about 517.1357287736.

The spelling of 138297278 in words is "one hundred thirty-eight million, two hundred ninety-seven thousand, two hundred seventy-eight".