138917644 has 12 divisors (see below), whose sum is σ = 244178424. Its totient is φ = 69152384.

The previous prime is 138917641. The next prime is 138917651. The reversal of 138917644 is 446719831.

It is a super-2 number, since 2×138917644² = 38596223629021472, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 138917644.

It is not an unprimeable number, because it can be changed into a prime (138917641) 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 3 ways as a sum of consecutive naturals, for example, 75589 + ... + 77404.

It is an arithmetic number, because the mean of its divisors is an integer number (20348202).

Almost surely, 2^138917644 is an apocalyptic number.

It is an amenable number.

138917644 is a deficient number, since it is larger than the sum of its proper divisors (105260780).

138917644 is a wasteful number, since it uses less digits than its factorization.

138917644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153224 (or 153222 counting only the distinct ones).

The product of its digits is 145152, while the sum is 43.

The square root of 138917644 is about 11786.3329326810. The cubic root of 138917644 is about 517.9078213858.

The spelling of 138917644 in words is "one hundred thirty-eight million, nine hundred seventeen thousand, six hundred forty-four".