138556980 has 180 divisors, whose sum is σ = 454178340. Its totient is φ = 35354880.

The previous prime is 138556973. The next prime is 138556981. The reversal of 138556980 is 89655831.

138556980 is a `hidden beast` number, since 1 + 3 + 8 + 5 + 569 + 80 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 37675044 + 100881936 = 6138^2 + 10044^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138556981) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1556776 + ... + 1556864.

It is an arithmetic number, because the mean of its divisors is an integer number (2523213).

Almost surely, 2^138556980 is an apocalyptic number.

138556980 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 138556980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227089170).

138556980 is an abundant number, since it is smaller than the sum of its proper divisors (315621360).

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

138556980 is a wasteful number, since it uses less digits than its factorization.

138556980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The square root of 138556980 is about 11771.0228952288. The cubic root of 138556980 is about 517.4592280417.

The spelling of 138556980 in words is "one hundred thirty-eight million, five hundred fifty-six thousand, nine hundred eighty".