138636623 has 4 divisors (see below), whose sum is σ = 138679560. Its totient is φ = 138593688.

The previous prime is 138636613. The next prime is 138636653. The reversal of 138636623 is 326636831.

138636623 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138636623 - 2¹⁸ = 138374479 is a prime.

It is a super-2 number, since 2×138636623² = 38440226473688258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138636613) 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, 16193 + ... + 23226.

It is an arithmetic number, because the mean of its divisors is an integer number (34669890).

Almost surely, 2^138636623 is an apocalyptic number.

138636623 is a deficient number, since it is larger than the sum of its proper divisors (42937).

138636623 is an equidigital number, since it uses as much as digits as its factorization.

138636623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42936.

The product of its digits is 93312, while the sum is 38.

The square root of 138636623 is about 11774.4054202325. The cubic root of 138636623 is about 517.5583547970.

The spelling of 138636623 in words is "one hundred thirty-eight million, six hundred thirty-six thousand, six hundred twenty-three".