21232424421 has 48 divisors (see below), whose sum is σ = 33325883136. Its totient is φ = 12948859008.

The previous prime is 21232424377. The next prime is 21232424441. The reversal of 21232424421 is 12442423212.

It is a happy number.

21232424421 is a `hidden beast` number, since 2 + 1 + 232 + 4 + 2 + 4 + 421 = 666.

It is not a de Polignac number, because 21232424421 - 2⁶ = 21232424357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232424441) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7022116 + ... + 7025138.

It is an arithmetic number, because the mean of its divisors is an integer number (694289232).

Almost surely, 2^21232424421 is an apocalyptic number.

It is an amenable number.

21232424421 is a deficient number, since it is larger than the sum of its proper divisors (12093458715).

21232424421 is a wasteful number, since it uses less digits than its factorization.

21232424421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3562 (or 3559 counting only the distinct ones).

The product of its digits is 6144, while the sum is 27.

Adding to 21232424421 its reverse (12442423212), we get a palindrome (33674847633).

The spelling of 21232424421 in words is "twenty-one billion, two hundred thirty-two million, four hundred twenty-four thousand, four hundred twenty-one".