138517998 has 16 divisors (see below), whose sum is σ = 280149840. Its totient is φ = 45653696.

The previous prime is 138517997. The next prime is 138518041. The reversal of 138517998 is 899715831.

138517998 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×138517998³ (a number of 25 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 138517998.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138517993) 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, 129165 + ... + 130232.

It is an arithmetic number, because the mean of its divisors is an integer number (17509365).

Almost surely, 2^138517998 is an apocalyptic number.

138517998 is an abundant number, since it is smaller than the sum of its proper divisors (141631842).

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

138517998 is a wasteful number, since it uses less digits than its factorization.

138517998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259491.

The product of its digits is 544320, while the sum is 51.

The square root of 138517998 is about 11769.3669328473. The cubic root of 138517998 is about 517.4106956915.

The spelling of 138517998 in words is "one hundred thirty-eight million, five hundred seventeen thousand, nine hundred ninety-eight".