21024411221 has 16 divisors (see below), whose sum is σ = 24193382400. Its totient is φ = 18069260400.

The previous prime is 21024411211. The next prime is 21024411307. The reversal of 21024411221 is 12211442012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21024411221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21024411193 and 21024411202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21024411211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4895 + ... + 205116.

It is an arithmetic number, because the mean of its divisors is an integer number (1512086400).

Almost surely, 2^21024411221 is an apocalyptic number.

It is an amenable number.

21024411221 is a deficient number, since it is larger than the sum of its proper divisors (3168971179).

21024411221 is a wasteful number, since it uses less digits than its factorization.

21024411221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210520.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21024411221 its reverse (12211442012), we get a palindrome (33235853233).

The spelling of 21024411221 in words is "twenty-one billion, twenty-four million, four hundred eleven thousand, two hundred twenty-one".