21211012073 has 2 divisors, whose sum is σ = 21211012074. Its totient is φ = 21211012072.

The previous prime is 21211012033. The next prime is 21211012087. The reversal of 21211012073 is 37021011212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19029374809 + 2181637264 = 137947^2 + 46708^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211012073 - 2²⁰ = 21209963497 is a prime.

It is not a weakly prime, because it can be changed into another prime (21211012033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605506036 + 10605506037.

It is an arithmetic number, because the mean of its divisors is an integer number (10605506037).

Almost surely, 2^21211012073 is an apocalyptic number.

It is an amenable number.

21211012073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211012073 is an equidigital number, since it uses as much as digits as its factorization.

21211012073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 20.

Adding to 21211012073 its reverse (37021011212), we get a palindrome (58232023285).

The spelling of 21211012073 in words is "twenty-one billion, two hundred eleven million, twelve thousand, seventy-three".