138128580 has 36 divisors (see below), whose sum is σ = 418990572. Its totient is φ = 36834240.

The previous prime is 138128531. The next prime is 138128597. The reversal of 138128580 is 85821831.

138128580 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 44116164 + 94012416 = 6642^2 + 9696^2 .

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

It is a super-2 number, since 2×138128580² = 38159009225632800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 383511 + ... + 383870.

It is an arithmetic number, because the mean of its divisors is an integer number (11638627).

Almost surely, 2^138128580 is an apocalyptic number.

138128580 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138128580 is an abundant number, since it is smaller than the sum of its proper divisors (280861992).

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

138128580 is a wasteful number, since it uses less digits than its factorization.

138128580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 767396 (or 767391 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 138128580 is about 11752.8115785118. The cubic root of 138128580 is about 516.9253721158.

The spelling of 138128580 in words is "one hundred thirty-eight million, one hundred twenty-eight thousand, five hundred eighty".