138633661 has 8 divisors (see below), whose sum is σ = 140364224. Its totient is φ = 136909440.

The previous prime is 138633641. The next prime is 138633679. The reversal of 138633661 is 166336831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138633661 - 2⁵ = 138633629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138633661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138633641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54136 + ... + 56638.

It is an arithmetic number, because the mean of its divisors is an integer number (17545528).

Almost surely, 2^138633661 is an apocalyptic number.

It is an amenable number.

138633661 is a deficient number, since it is larger than the sum of its proper divisors (1730563).

138633661 is an equidigital number, since it uses as much as digits as its factorization.

138633661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3171.

The product of its digits is 46656, while the sum is 37.

The square root of 138633661 is about 11774.2796382624. The cubic root of 138633661 is about 517.5546688572.

The spelling of 138633661 in words is "one hundred thirty-eight million, six hundred thirty-three thousand, six hundred sixty-one".