138642560 has 96 divisors (see below), whose sum is σ = 385642620. Its totient is φ = 47523840.

The previous prime is 138642557. The next prime is 138642583. The reversal of 138642560 is 65246831.

It can be written as a sum of positive squares in 2 ways, for example, as 136983616 + 1658944 = 11704^2 + 1288^2 .

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 138642560.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29150 + ... + 33570.

Almost surely, 2^138642560 is an apocalyptic number.

138642560 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 138642560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192821310).

138642560 is an abundant number, since it is smaller than the sum of its proper divisors (247000060).

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

138642560 is an equidigital number, since it uses as much as digits as its factorization.

138642560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4454 (or 4435 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 138642560 is about 11774.6575321748. The cubic root of 138642560 is about 517.5657426960.

The spelling of 138642560 in words is "one hundred thirty-eight million, six hundred forty-two thousand, five hundred sixty".