138943636 has 24 divisors (see below), whose sum is σ = 262712520. Its totient is φ = 63917952.

The previous prime is 138943633. The next prime is 138943691. The reversal of 138943636 is 636349831.

It can be written as a sum of positive squares in 4 ways, for example, as 9120400 + 129823236 = 3020^2 + 11394^2 .

It is a junction number, because it is equal to n+sod(n) for n = 138943592 and 138943601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138943633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12270 + ... + 20698.

It is an arithmetic number, because the mean of its divisors is an integer number (10946355).

Almost surely, 2^138943636 is an apocalyptic number.

It is an amenable number.

138943636 is a deficient number, since it is larger than the sum of its proper divisors (123768884).

138943636 is a wasteful number, since it uses less digits than its factorization.

138943636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8763 (or 8761 counting only the distinct ones).

The product of its digits is 279936, while the sum is 43.

The square root of 138943636 is about 11787.4355141396. The cubic root of 138943636 is about 517.9401201883.

The spelling of 138943636 in words is "one hundred thirty-eight million, nine hundred forty-three thousand, six hundred thirty-six".