21002110004921 has 2 divisors, whose sum is σ = 21002110004922. Its totient is φ = 21002110004920.

The previous prime is 21002110004861. The next prime is 21002110004923. The reversal of 21002110004921 is 12940001120012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14986274606521 + 6015835398400 = 3871211^2 + 2452720^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002110004921 - 2²⁶ = 21002042896057 is a prime.

Together with 21002110004923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21002110004923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501055002460 + 10501055002461.

It is an arithmetic number, because the mean of its divisors is an integer number (10501055002461).

Almost surely, 2^{21002110004921} is an apocalyptic number.

It is an amenable number.

21002110004921 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002110004921 is an equidigital number, since it uses as much as digits as its factorization.

21002110004921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

Adding to 21002110004921 its reverse (12940001120012), we get a palindrome (33942111124933).

The spelling of 21002110004921 in words is "twenty-one trillion, two billion, one hundred ten million, four thousand, nine hundred twenty-one".