19221879 has 4 divisors (see below), whose sum is σ = 25629176. Its totient is φ = 12814584.

The previous prime is 19221827. The next prime is 19221913. The reversal of 19221879 is 97812291.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97812291 = 3 ⋅32604097.

It is not a de Polignac number, because 19221879 - 2⁸ = 19221623 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 (19221379) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3203644 + ... + 3203649.

It is an arithmetic number, because the mean of its divisors is an integer number (6407294).

Almost surely, 2^19221879 is an apocalyptic number.

19221879 is a deficient number, since it is larger than the sum of its proper divisors (6407297).

19221879 is an equidigital number, since it uses as much as digits as its factorization.

19221879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6407296.

The product of its digits is 18144, while the sum is 39.

The square root of 19221879 is about 4384.2763370937. The cubic root of 19221879 is about 267.8748533915.

It can be divided in two parts, 19221 and 879, that added together give a triangular number (20100 = T₂₀₀).

The spelling of 19221879 in words is "nineteen million, two hundred twenty-one thousand, eight hundred seventy-nine".