138480840 has 128 divisors (see below), whose sum is σ = 467596800. Its totient is φ = 36904896.

The previous prime is 138480803. The next prime is 138480869. The reversal of 138480840 is 48084831.

138480840 is a `hidden beast` number, since 138 + 480 + 8 + 40 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 138480795 and 138480804.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86689 + ... + 88271.

It is an arithmetic number, because the mean of its divisors is an integer number (3653100).

Almost surely, 2^138480840 is an apocalyptic number.

138480840 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 138480840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (233798400).

138480840 is an abundant number, since it is smaller than the sum of its proper divisors (329115960).

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

138480840 is an equidigital number, since it uses as much as digits as its factorization.

138480840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615 (or 1593 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 138480840 is about 11767.7882373877. The cubic root of 138480840 is about 517.3644257331.

The spelling of 138480840 in words is "one hundred thirty-eight million, four hundred eighty thousand, eight hundred forty".