138661944 has 32 divisors (see below), whose sum is σ = 347349120. Its totient is φ = 46128096.

The previous prime is 138661931. The next prime is 138661949. The reversal of 138661944 is 449166831.

It is a junction number, because it is equal to n+sod(n) for n = 138661896 and 138661905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138661949) 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, 7029 + ... + 18075.

It is an arithmetic number, because the mean of its divisors is an integer number (10854660).

Almost surely, 2^138661944 is an apocalyptic number.

It is an amenable number.

138661944 is an abundant number, since it is smaller than the sum of its proper divisors (208687176).

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

138661944 is a wasteful number, since it uses less digits than its factorization.

138661944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11579 (or 11575 counting only the distinct ones).

The product of its digits is 124416, while the sum is 42.

The square root of 138661944 is about 11775.4806271337. The cubic root of 138661944 is about 517.5898623382.

The spelling of 138661944 in words is "one hundred thirty-eight million, six hundred sixty-one thousand, nine hundred forty-four".