21102028511 has 2 divisors, whose sum is σ = 21102028512. Its totient is φ = 21102028510.

The previous prime is 21102028487. The next prime is 21102028531. The reversal of 21102028511 is 11582020112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21102028511 - 2¹⁰ = 21102027487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21102028531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551014255 + 10551014256.

It is an arithmetic number, because the mean of its divisors is an integer number (10551014256).

Almost surely, 2^21102028511 is an apocalyptic number.

21102028511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102028511 is an equidigital number, since it uses as much as digits as its factorization.

21102028511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 320, while the sum is 23.

Adding to 21102028511 its reverse (11582020112), we get a palindrome (32684048623).

The spelling of 21102028511 in words is "twenty-one billion, one hundred two million, twenty-eight thousand, five hundred eleven".