21124200342021 has 48 divisors (see below), whose sum is σ = 34210627007040. Its totient is φ = 11545808252160.

The previous prime is 21124200341977. The next prime is 21124200342031. The reversal of 21124200342021 is 12024300242112.

It is not a de Polignac number, because 21124200342021 - 2⁹ = 21124200341509 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21124200341982 and 21124200342000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124200342031) 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, 22699200 + ... + 23611481.

It is an arithmetic number, because the mean of its divisors is an integer number (712721395980).

Almost surely, 2^{21124200342021} is an apocalyptic number.

21124200342021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21124200342021 is a deficient number, since it is larger than the sum of its proper divisors (13086426665019).

21124200342021 is a wasteful number, since it uses less digits than its factorization.

21124200342021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46310834 (or 46310827 counting only the distinct ones).

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

Adding to 21124200342021 its reverse (12024300242112), we get a palindrome (33148500584133).

Subtracting from 21124200342021 its reverse (12024300242112), we obtain a palindrome (9099900099909).

The spelling of 21124200342021 in words is "twenty-one trillion, one hundred twenty-four billion, two hundred million, three hundred forty-two thousand, twenty-one".