138840930 has 48 divisors (see below), whose sum is σ = 364323960. Its totient is φ = 36681984.

The previous prime is 138840917. The next prime is 138840943. The reversal of 138840930 is 39048831.

It is an interprime number because it is at equal distance from previous prime (138840917) and next prime (138840943).

It can be written as a sum of positive squares in 4 ways, for example, as 115541001 + 23299929 = 10749^2 + 4827^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2734 + ... + 16886.

Almost surely, 2^138840930 is an apocalyptic number.

138840930 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 138840930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182161980).

138840930 is an abundant number, since it is smaller than the sum of its proper divisors (225483030).

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

138840930 is a wasteful number, since it uses less digits than its factorization.

138840930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14275 (or 14272 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 138840930 is about 11783.0781207628. The cubic root of 138840930 is about 517.8124696960.

The spelling of 138840930 in words is "one hundred thirty-eight million, eight hundred forty thousand, nine hundred thirty".