21365586605 has 32 divisors (see below), whose sum is σ = 28412467200. Its totient is φ = 15293275200.

The previous prime is 21365586569. The next prime is 21365586617. The reversal of 21365586605 is 50668556312.

It is not a de Polignac number, because 21365586605 - 2¹⁴ = 21365570221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21365586605.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2412776 + ... + 2421614.

It is an arithmetic number, because the mean of its divisors is an integer number (887889600).

Almost surely, 2^21365586605 is an apocalyptic number.

It is an amenable number.

21365586605 is a deficient number, since it is larger than the sum of its proper divisors (7046880595).

21365586605 is a wasteful number, since it uses less digits than its factorization.

21365586605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9545.

The product of its (nonzero) digits is 1296000, while the sum is 47.

The spelling of 21365586605 in words is "twenty-one billion, three hundred sixty-five million, five hundred eighty-six thousand, six hundred five".