21461823205 has 8 divisors (see below), whose sum is σ = 25884920952. Its totient is φ = 17082303168.

The previous prime is 21461823197. The next prime is 21461823263. The reversal of 21461823205 is 50232816412.

It can be written as a sum of positive squares in 4 ways, for example, as 7782415524 + 13679407681 = 88218^2 + 116959^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21461823205 - 2³ = 21461823197 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 10893342 + ... + 10895311.

It is an arithmetic number, because the mean of its divisors is an integer number (3235615119).

Almost surely, 2^21461823205 is an apocalyptic number.

It is an amenable number.

21461823205 is a deficient number, since it is larger than the sum of its proper divisors (4423097747).

21461823205 is a wasteful number, since it uses less digits than its factorization.

21461823205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21788855.

The product of its (nonzero) digits is 23040, while the sum is 34.

The spelling of 21461823205 in words is "twenty-one billion, four hundred sixty-one million, eight hundred twenty-three thousand, two hundred five".