21424232020 has 12 divisors (see below), whose sum is σ = 44990887284. Its totient is φ = 8569692800.

The previous prime is 21424232017. The next prime is 21424232041. The reversal of 21424232020 is 2023242412.

It can be written as a sum of positive squares in 2 ways, for example, as 9091241104 + 12332990916 = 95348^2 + 111054^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21424231982 and 21424232000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535605781 + ... + 535605820.

It is an arithmetic number, because the mean of its divisors is an integer number (3749240607).

Almost surely, 2^21424232020 is an apocalyptic number.

21424232020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21424232020 is an abundant number, since it is smaller than the sum of its proper divisors (23566655264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21424232020 is a wasteful number, since it uses less digits than its factorization.

21424232020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071211610 (or 1071211608 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21424232020 its reverse (2023242412), we get a palindrome (23447474432).

The spelling of 21424232020 in words is "twenty-one billion, four hundred twenty-four million, two hundred thirty-two thousand, twenty".