138888849 has 8 divisors (see below), whose sum is σ = 202020192. Its totient is φ = 84175040.

The previous prime is 138888847. The next prime is 138888857. The reversal of 138888849 is 948888831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138888849 - 2¹ = 138888847 is a prime.

It is a super-2 number, since 2×138888849² = 38580224753089602, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138888847) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2104344 + ... + 2104409.

It is an arithmetic number, because the mean of its divisors is an integer number (25252524).

Almost surely, 2^138888849 is an apocalyptic number.

It is an amenable number.

138888849 is a deficient number, since it is larger than the sum of its proper divisors (63131343).

138888849 is a wasteful number, since it uses less digits than its factorization.

138888849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208767.

The product of its digits is 3538944, while the sum is 57.

The square root of 138888849 is about 11785.1113274334. Note that the first 3 decimals coincide. The cubic root of 138888849 is about 517.8720347480.

The spelling of 138888849 in words is "one hundred thirty-eight million, eight hundred eighty-eight thousand, eight hundred forty-nine".