138998 has 4 divisors (see below), whose sum is σ = 208500. Its totient is φ = 69498.

The previous prime is 138977. The next prime is 139021. The reversal of 138998 is 899831.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 138998.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 34748 + ... + 34751.

It is an arithmetic number, because the mean of its divisors is an integer number (52125).

2¹³⁸⁹⁹⁸ is an apocalyptic number.

138998 is a deficient number, since it is larger than the sum of its proper divisors (69502).

138998 is an equidigital number, since it uses as much as digits as its factorization.

138998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69501.

The product of its digits is 15552, while the sum is 38.

The square root of 138998 is about 372.8243554276. The cubic root of 138998 is about 51.8007662265.

The spelling of 138998 in words is "one hundred thirty-eight thousand, nine hundred ninety-eight".