21194439269 has 4 divisors (see below), whose sum is σ = 21251261196. Its totient is φ = 21137617344.

The previous prime is 21194439221. The next prime is 21194439283. The reversal of 21194439269 is 96293449112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14122470244 + 7071969025 = 118838^2 + 84095^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21194439269 is a prime.

It is a super-2 number, since 2×21194439269² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21194439289) 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, 28410404 + ... + 28411149.

It is an arithmetic number, because the mean of its divisors is an integer number (5312815299).

Almost surely, 2^21194439269 is an apocalyptic number.

It is an amenable number.

21194439269 is a deficient number, since it is larger than the sum of its proper divisors (56821927).

21194439269 is an equidigital number, since it uses as much as digits as its factorization.

21194439269 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56821926.

The product of its digits is 839808, while the sum is 50.

The spelling of 21194439269 in words is "twenty-one billion, one hundred ninety-four million, four hundred thirty-nine thousand, two hundred sixty-nine".