21113024521 has 2 divisors, whose sum is σ = 21113024522. Its totient is φ = 21113024520.

The previous prime is 21113024519. The next prime is 21113024573. The reversal of 21113024521 is 12542031112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18295538121 + 2817486400 = 135261^2 + 53080^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113024521 - 2¹ = 21113024519 is a prime.

Together with 21113024519, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21113024492 and 21113024501.

It is not a weakly prime, because it can be changed into another prime (21113024221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556512260 + 10556512261.

It is an arithmetic number, because the mean of its divisors is an integer number (10556512261).

Almost surely, 2^21113024521 is an apocalyptic number.

It is an amenable number.

21113024521 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113024521 is an equidigital number, since it uses as much as digits as its factorization.

21113024521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 22.

Adding to 21113024521 its reverse (12542031112), we get a palindrome (33655055633).

The spelling of 21113024521 in words is "twenty-one billion, one hundred thirteen million, twenty-four thousand, five hundred twenty-one".