138726828 has 36 divisors (see below), whose sum is σ = 369128760. Its totient is φ = 43808256.

The previous prime is 138726827. The next prime is 138726857. The reversal of 138726828 is 828627831.

138726828 is a `hidden beast` number, since 1 + 387 + 268 + 2 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (138726827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 100725 + ... + 102092.

Almost surely, 2^138726828 is an apocalyptic number.

138726828 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138726828 is an abundant number, since it is smaller than the sum of its proper divisors (230401932).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138726828 is a wasteful number, since it uses less digits than its factorization.

138726828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202846 (or 202841 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 138726828 is about 11778.2353516985. The cubic root of 138726828 is about 517.6705815868.

The spelling of 138726828 in words is "one hundred thirty-eight million, seven hundred twenty-six thousand, eight hundred twenty-eight".