138861684 has 36 divisors (see below), whose sum is σ = 378013636. Its totient is φ = 42726528.

The previous prime is 138861683. The next prime is 138861691. The reversal of 138861684 is 486168831.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 66781584 + 72080100 = 8172^2 + 8490^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138861683) 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 11 ways as a sum of consecutive naturals, for example, 147889 + ... + 148824.

Almost surely, 2^138861684 is an apocalyptic number.

It is an amenable number.

138861684 is an abundant number, since it is smaller than the sum of its proper divisors (239151952).

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

138861684 is a wasteful number, since it uses less digits than its factorization.

138861684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296736 (or 296731 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 138861684 is about 11783.9587575653. The cubic root of 138861684 is about 517.8382693517.

The spelling of 138861684 in words is "one hundred thirty-eight million, eight hundred sixty-one thousand, six hundred eighty-four".