138535220 has 12 divisors (see below), whose sum is σ = 290924004. Its totient is φ = 55414080.

The previous prime is 138535219. The next prime is 138535223. The reversal of 138535220 is 22535831.

It can be written as a sum of positive squares in 2 ways, for example, as 99121936 + 39413284 = 9956^2 + 6278^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138535223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3463361 + ... + 3463400.

It is an arithmetic number, because the mean of its divisors is an integer number (24243667).

Almost surely, 2^138535220 is an apocalyptic number.

138535220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138535220 is an abundant number, since it is smaller than the sum of its proper divisors (152388784).

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

138535220 is a wasteful number, since it uses less digits than its factorization.

138535220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6926770 (or 6926768 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 138535220 is about 11770.0985552373. The cubic root of 138535220 is about 517.4321380982.

The spelling of 138535220 in words is "one hundred thirty-eight million, five hundred thirty-five thousand, two hundred twenty".