21726831419 has 4 divisors (see below), whose sum is σ = 23004880344. Its totient is φ = 20448782496.

The previous prime is 21726831403. The next prime is 21726831421. The reversal of 21726831419 is 91413862712.

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

It is a cyclic number.

It is not a de Polignac number, because 21726831419 - 2⁴ = 21726831403 is a prime.

It is a super-2 number, since 2×21726831419² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21726831419.

It is not an unprimeable number, because it can be changed into a prime (21726831439) 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, 639024437 + ... + 639024470.

It is an arithmetic number, because the mean of its divisors is an integer number (5751220086).

Almost surely, 2^21726831419 is an apocalyptic number.

21726831419 is a deficient number, since it is larger than the sum of its proper divisors (1278048925).

21726831419 is a wasteful number, since it uses less digits than its factorization.

21726831419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1278048924.

The product of its digits is 145152, while the sum is 44.

The spelling of 21726831419 in words is "twenty-one billion, seven hundred twenty-six million, eight hundred thirty-one thousand, four hundred nineteen".