21385522799 has 2 divisors, whose sum is σ = 21385522800. Its totient is φ = 21385522798.

The previous prime is 21385522747. The next prime is 21385522817. The reversal of 21385522799 is 99722558312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21385522799 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21385522799.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21385522729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10692761399 + 10692761400.

It is an arithmetic number, because the mean of its divisors is an integer number (10692761400).

Almost surely, 2^21385522799 is an apocalyptic number.

21385522799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21385522799 is an equidigital number, since it uses as much as digits as its factorization.

21385522799 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2721600, while the sum is 53.

The spelling of 21385522799 in words is "twenty-one billion, three hundred eighty-five million, five hundred twenty-two thousand, seven hundred ninety-nine".