138891998 has 32 divisors (see below), whose sum is σ = 244508160. Its totient is φ = 57944160.

The previous prime is 138891983. The next prime is 138892001. The reversal of 138891998 is 899198831.

It is a happy number.

138891998 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87173 + ... + 88751.

It is an arithmetic number, because the mean of its divisors is an integer number (7640880).

Almost surely, 2^138891998 is an apocalyptic number.

138891998 is a deficient number, since it is larger than the sum of its proper divisors (105616162).

138891998 is a wasteful number, since it uses less digits than its factorization.

138891998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1752.

The product of its digits is 1119744, while the sum is 56.

The square root of 138891998 is about 11785.2449274506. The cubic root of 138891998 is about 517.8759485893.

The spelling of 138891998 in words is "one hundred thirty-eight million, eight hundred ninety-one thousand, nine hundred ninety-eight".