138019860 has 108 divisors (see below), whose sum is σ = 460252884. Its totient is φ = 33454080.

The previous prime is 138019841. The next prime is 138019867. The reversal of 138019860 is 68910831.

It can be written as a sum of positive squares in 2 ways, for example, as 48944016 + 89075844 = 6996^2 + 9438^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138019867) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 18612 + ... + 24948.

Almost surely, 2^138019860 is an apocalyptic number.

138019860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138019860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230126442).

138019860 is an abundant number, since it is smaller than the sum of its proper divisors (322233024).

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

138019860 is a wasteful number, since it uses less digits than its factorization.

138019860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6374 (or 6358 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 138019860 is about 11748.1853917956. The cubic root of 138019860 is about 516.7897137850.

The spelling of 138019860 in words is "one hundred thirty-eight million, nineteen thousand, eight hundred sixty".