19998279 has 32 divisors (see below), whose sum is σ = 35648000. Its totient is φ = 10824192.

The previous prime is 19998263. The next prime is 19998337. The reversal of 19998279 is 97289991.

It is not a de Polignac number, because 19998279 - 2⁴ = 19998263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19998229) 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 31 ways as a sum of consecutive naturals, for example, 807 + ... + 6375.

It is an arithmetic number, because the mean of its divisors is an integer number (1114000).

Almost surely, 2^19998279 is an apocalyptic number.

19998279 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

19998279 is a deficient number, since it is larger than the sum of its proper divisors (15649721).

19998279 is a wasteful number, since it uses less digits than its factorization.

19998279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5604 (or 5598 counting only the distinct ones).

The product of its digits is 734832, while the sum is 54.

The square root of 19998279 is about 4471.9435372106. The cubic root of 19998279 is about 271.4339755816.

The spelling of 19998279 in words is "nineteen million, nine hundred ninety-eight thousand, two hundred seventy-nine".