19800223979 has 4 divisors (see below), whose sum is σ = 19981877520. Its totient is φ = 19618570440.

The previous prime is 19800223939. The next prime is 19800223991. The reversal of 19800223979 is 97932200891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97932200891 = 7 ⋅13990314413.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19800223979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19800223909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90826607 + ... + 90826824.

It is an arithmetic number, because the mean of its divisors is an integer number (4995469380).

Almost surely, 2^19800223979 is an apocalyptic number.

19800223979 is a deficient number, since it is larger than the sum of its proper divisors (181653541).

19800223979 is a wasteful number, since it uses less digits than its factorization.

19800223979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181653540.

The product of its (nonzero) digits is 489888, while the sum is 50.

The spelling of 19800223979 in words is "nineteen billion, eight hundred million, two hundred twenty-three thousand, nine hundred seventy-nine".