138643252 has 18 divisors (see below), whose sum is σ = 266688674. Its totient is φ = 63019440.

The previous prime is 138643243. The next prime is 138643261. The reversal of 138643252 is 252346831.

It is an interprime number because it is at equal distance from previous prime (138643243) and next prime (138643261).

It can be written as a sum of positive squares in only one way, i.e., 114789796 + 23853456 = 10714^2 + 4884^2 .

It is a congruent 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 5 ways as a sum of consecutive naturals, for example, 142743 + ... + 143710.

Almost surely, 2^138643252 is an apocalyptic number.

It is an amenable number.

138643252 is a deficient number, since it is larger than the sum of its proper divisors (128045422).

138643252 is a wasteful number, since it uses less digits than its factorization.

138643252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286479 (or 286466 counting only the distinct ones).

The product of its digits is 34560, while the sum is 34.

The square root of 138643252 is about 11774.6869172815. The cubic root of 138643252 is about 517.5666037950.

The spelling of 138643252 in words is "one hundred thirty-eight million, six hundred forty-three thousand, two hundred fifty-two".