21279422819 has 4 divisors (see below), whose sum is σ = 21732176544. Its totient is φ = 20826669096.

The previous prime is 21279422789. The next prime is 21279422849. The reversal of 21279422819 is 91822497212.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21279422789) and next prime (21279422849).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21279422819 is a prime.

It is a super-3 number, since 3×21279422819³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 452753677 = 21279422819 / (2 + 1 + 2 + 7 + 9 + 4 + 2 + 2 + 8 + 1 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21279422849) 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, 226376792 + ... + 226376885.

It is an arithmetic number, because the mean of its divisors is an integer number (5433044136).

Almost surely, 2^21279422819 is an apocalyptic number.

21279422819 is a deficient number, since it is larger than the sum of its proper divisors (452753725).

21279422819 is an equidigital number, since it uses as much as digits as its factorization.

21279422819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452753724.

The product of its digits is 290304, while the sum is 47.

The spelling of 21279422819 in words is "twenty-one billion, two hundred seventy-nine million, four hundred twenty-two thousand, eight hundred nineteen".