19998811 has 12 divisors (see below), whose sum is σ = 24489480. Its totient is φ = 16238880.

The previous prime is 19998809. The next prime is 19998841. The reversal of 19998811 is 11889991.

It is not a de Polignac number, because 19998811 - 2¹ = 19998809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19998841) 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 11 ways as a sum of consecutive naturals, for example, 9810 + ... + 11671.

It is an arithmetic number, because the mean of its divisors is an integer number (2040790).

Almost surely, 2^19998811 is an apocalyptic number.

19998811 is a deficient number, since it is larger than the sum of its proper divisors (4490669).

19998811 is a wasteful number, since it uses less digits than its factorization.

19998811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21514 (or 21507 counting only the distinct ones).

The product of its digits is 46656, while the sum is 46.

The square root of 19998811 is about 4472.0030187825. The cubic root of 19998811 is about 271.4363824820.

The spelling of 19998811 in words is "nineteen million, nine hundred ninety-eight thousand, eight hundred eleven".