21804569805 has 8 divisors (see below), whose sum is σ = 34887311712. Its totient is φ = 11629103888.

The previous prime is 21804569797. The next prime is 21804569837. The reversal of 21804569805 is 50896540812.

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 21804569805 - 2³ = 21804569797 is a prime.

It is a super-2 number, since 2×21804569805² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 726818979 + ... + 726819008.

It is an arithmetic number, because the mean of its divisors is an integer number (4360913964).

Almost surely, 2^21804569805 is an apocalyptic number.

It is an amenable number.

21804569805 is a deficient number, since it is larger than the sum of its proper divisors (13082741907).

21804569805 is a wasteful number, since it uses less digits than its factorization.

21804569805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1453637995.

The product of its (nonzero) digits is 691200, while the sum is 48.

The spelling of 21804569805 in words is "twenty-one billion, eight hundred four million, five hundred sixty-nine thousand, eight hundred five".