19998923 has 16 divisors (see below), whose sum is σ = 23639040. Its totient is φ = 16564416.

The previous prime is 19998917. The next prime is 19998943. The reversal of 19998923 is 32989991.

It is a cyclic number.

It is not a de Polignac number, because 19998923 - 2⁶ = 19998859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19998943) 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 15 ways as a sum of consecutive naturals, for example, 28940 + ... + 29622.

It is an arithmetic number, because the mean of its divisors is an integer number (1477440).

Almost surely, 2^19998923 is an apocalyptic number.

19998923 is a deficient number, since it is larger than the sum of its proper divisors (3640117).

19998923 is an equidigital number, since it uses as much as digits as its factorization.

19998923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 826.

The product of its digits is 314928, while the sum is 50.

The square root of 19998923 is about 4472.0155411179. The cubic root of 19998923 is about 271.4368891924.

The spelling of 19998923 in words is "nineteen million, nine hundred ninety-eight thousand, nine hundred twenty-three".