19818998 has 4 divisors (see below), whose sum is σ = 29728500. Its totient is φ = 9909498.

The previous prime is 19818983. The next prime is 19819003. The reversal of 19818998 is 89981891.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954748 + ... + 4954751.

It is an arithmetic number, because the mean of its divisors is an integer number (7432125).

Almost surely, 2^19818998 is an apocalyptic number.

19818998 is a deficient number, since it is larger than the sum of its proper divisors (9909502).

19818998 is an equidigital number, since it uses as much as digits as its factorization.

19818998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9909501.

The product of its digits is 373248, while the sum is 53.

The square root of 19818998 is about 4451.8533219323. The cubic root of 19818998 is about 270.6204205516.

The spelling of 19818998 in words is "nineteen million, eight hundred eighteen thousand, nine hundred ninety-eight".