138618444 has 24 divisors (see below), whose sum is σ = 328272448. Its totient is φ = 45516240.

The previous prime is 138618443. The next prime is 138618449. The reversal of 138618444 is 444816831.

It is a super-2 number, since 2×138618444² = 38430146033962272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138618443) 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, 85402 + ... + 87009.

Almost surely, 2^138618444 is an apocalyptic number.

It is an amenable number.

138618444 is an abundant number, since it is smaller than the sum of its proper divisors (189654004).

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

138618444 is a wasteful number, since it uses less digits than its factorization.

138618444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172485 (or 172483 counting only the distinct ones).

The product of its digits is 73728, while the sum is 39.

The square root of 138618444 is about 11773.6334238841. The cubic root of 138618444 is about 517.5357318556.

The spelling of 138618444 in words is "one hundred thirty-eight million, six hundred eighteen thousand, four hundred forty-four".