138225690 has 112 divisors (see below), whose sum is σ = 379944288. Its totient is φ = 36181728.

The previous prime is 138225649. The next prime is 138225701. The reversal of 138225690 is 96522831.

138225690 is a `hidden beast` number, since 13 + 82 + 2 + 569 + 0 = 666.

It is a super-2 number, since 2×138225690² = 38212682751952200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

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 55 ways as a sum of consecutive naturals, for example, 488289 + ... + 488571.

Almost surely, 2^138225690 is an apocalyptic number.

138225690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 138225690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189972144).

138225690 is an abundant number, since it is smaller than the sum of its proper divisors (241718598).

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

138225690 is an equidigital number, since it uses as much as digits as its factorization.

138225690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 138225690 is about 11756.9422045020. The cubic root of 138225690 is about 517.0464835797.

It can be divided in two parts, 1382 and 25690, that added together give a palindrome (27072).

The spelling of 138225690 in words is "one hundred thirty-eight million, two hundred twenty-five thousand, six hundred ninety".