21823831421 has 16 divisors (see below), whose sum is σ = 25243430400. Its totient is φ = 18480071808.

The previous prime is 21823831369. The next prime is 21823831427. The reversal of 21823831421 is 12413832812.

It is a cyclic number.

It is not a de Polignac number, because 21823831421 - 2¹⁰ = 21823830397 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 (21823831427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 741260 + ... + 770138.

It is an arithmetic number, because the mean of its divisors is an integer number (1577714400).

Almost surely, 2^21823831421 is an apocalyptic number.

It is an amenable number.

21823831421 is a deficient number, since it is larger than the sum of its proper divisors (3419598979).

21823831421 is a wasteful number, since it uses less digits than its factorization.

21823831421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30188.

The product of its digits is 18432, while the sum is 35.

The spelling of 21823831421 in words is "twenty-one billion, eight hundred twenty-three million, eight hundred thirty-one thousand, four hundred twenty-one".