21650210009 has 2 divisors, whose sum is σ = 21650210010. Its totient is φ = 21650210008.

The previous prime is 21650209981. The next prime is 21650210033. The reversal of 21650210009 is 90001205612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10967953984 + 10682256025 = 104728^2 + 103355^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21650210009 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21650210009.

It is not a weakly prime, because it can be changed into another prime (21650210059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10825105004 + 10825105005.

It is an arithmetic number, because the mean of its divisors is an integer number (10825105005).

Almost surely, 2^21650210009 is an apocalyptic number.

It is an amenable number.

21650210009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21650210009 is an equidigital number, since it uses as much as digits as its factorization.

21650210009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 26.

The spelling of 21650210009 in words is "twenty-one billion, six hundred fifty million, two hundred ten thousand, nine".