138722640 has 160 divisors (see below), whose sum is σ = 498825216. Its totient is φ = 31234560.

The previous prime is 138722627. The next prime is 138722641. The reversal of 138722640 is 46227831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138722641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 118699 + ... + 119861.

Almost surely, 2^138722640 is an apocalyptic number.

138722640 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 138722640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249412608).

138722640 is an abundant number, since it is smaller than the sum of its proper divisors (360102576).

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

138722640 is a wasteful number, since it uses less digits than its factorization.

138722640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1257 (or 1251 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 138722640 is about 11778.0575648109. The cubic root of 138722640 is about 517.6653722455.

The spelling of 138722640 in words is "one hundred thirty-eight million, seven hundred twenty-two thousand, six hundred forty".