21421224231 has 24 divisors (see below), whose sum is σ = 31402385280. Its totient is φ = 12979171920.

The previous prime is 21421224197. The next prime is 21421224241. The reversal of 21421224231 is 13242212412.

It is not a de Polignac number, because 21421224231 - 2¹⁰ = 21421223207 is a prime.

It is a super-2 number, since 2×21421224231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421224241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2594596 + ... + 2602838.

It is an arithmetic number, because the mean of its divisors is an integer number (1308432720).

Almost surely, 2^21421224231 is an apocalyptic number.

21421224231 is a deficient number, since it is larger than the sum of its proper divisors (9981161049).

21421224231 is a wasteful number, since it uses less digits than its factorization.

21421224231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15427 (or 15416 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

Adding to 21421224231 its reverse (13242212412), we get a palindrome (34663436643).

The spelling of 21421224231 in words is "twenty-one billion, four hundred twenty-one million, two hundred twenty-four thousand, two hundred thirty-one".