138019540 has 12 divisors (see below), whose sum is σ = 289841076. Its totient is φ = 55207808.

The previous prime is 138019529. The next prime is 138019547. The reversal of 138019540 is 45910831.

It can be written as a sum of positive squares in 2 ways, for example, as 14409616 + 123609924 = 3796^2 + 11118^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138019547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3450469 + ... + 3450508.

It is an arithmetic number, because the mean of its divisors is an integer number (24153423).

Almost surely, 2^138019540 is an apocalyptic number.

138019540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138019540 is an abundant number, since it is smaller than the sum of its proper divisors (151821536).

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

138019540 is a wasteful number, since it uses less digits than its factorization.

138019540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6900986 (or 6900984 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 138019540 is about 11748.1717726632. The cubic root of 138019540 is about 516.7893143912.

The spelling of 138019540 in words is "one hundred thirty-eight million, nineteen thousand, five hundred forty".