21004424231 has 12 divisors (see below), whose sum is σ = 24777858960. Its totient is φ = 17750214720.

The previous prime is 21004424219. The next prime is 21004424249. The reversal of 21004424231 is 13242440012.

It is not a de Polignac number, because 21004424231 - 2²² = 21000229927 is a prime.

It is a super-2 number, since 2×21004424231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21004424197 and 21004424206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004424281) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3015266 + ... + 3022223.

It is an arithmetic number, because the mean of its divisors is an integer number (2064821580).

Almost surely, 2^21004424231 is an apocalyptic number.

21004424231 is a deficient number, since it is larger than the sum of its proper divisors (3773434729).

21004424231 is an equidigital number, since it uses as much as digits as its factorization.

21004424231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6037574 (or 6037567 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21004424231 its reverse (13242440012), we get a palindrome (34246864243).

The spelling of 21004424231 in words is "twenty-one billion, four million, four hundred twenty-four thousand, two hundred thirty-one".