21636720299 has 2 divisors, whose sum is σ = 21636720300. Its totient is φ = 21636720298.

The previous prime is 21636720283. The next prime is 21636720319. The reversal of 21636720299 is 99202763612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21636720299 - 2⁴ = 21636720283 is a prime.

It is not a weakly prime, because it can be changed into another prime (21636720239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10818360149 + 10818360150.

It is an arithmetic number, because the mean of its divisors is an integer number (10818360150).

Almost surely, 2^21636720299 is an apocalyptic number.

21636720299 is a deficient number, since it is larger than the sum of its proper divisors (1).

21636720299 is an equidigital number, since it uses as much as digits as its factorization.

21636720299 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 47.

The spelling of 21636720299 in words is "twenty-one billion, six hundred thirty-six million, seven hundred twenty thousand, two hundred ninety-nine".