21102110641 has 2 divisors, whose sum is σ = 21102110642. Its totient is φ = 21102110640.

The previous prime is 21102110639. The next prime is 21102110671. The reversal of 21102110641 is 14601120112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16051876416 + 5050234225 = 126696^2 + 71065^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102110641 - 2¹ = 21102110639 is a prime.

Together with 21102110639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21102110621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551055320 + 10551055321.

It is an arithmetic number, because the mean of its divisors is an integer number (10551055321).

Almost surely, 2^21102110641 is an apocalyptic number.

It is an amenable number.

21102110641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102110641 is an equidigital number, since it uses as much as digits as its factorization.

21102110641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 21102110641 its reverse (14601120112), we get a palindrome (35703230753).

The spelling of 21102110641 in words is "twenty-one billion, one hundred two million, one hundred ten thousand, six hundred forty-one".