21804168408 has 32 divisors (see below), whose sum is σ = 59465914560. Its totient is φ = 6607323680.

The previous prime is 21804168367. The next prime is 21804168437. The reversal of 21804168408 is 80486140812.

It is a self number, because there is not a number n which added to its sum of digits gives 21804168408.

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, 41295510 + ... + 41296037.

It is an arithmetic number, because the mean of its divisors is an integer number (1858309830).

Almost surely, 2^21804168408 is an apocalyptic number.

It is an amenable number.

21804168408 is an abundant number, since it is smaller than the sum of its proper divisors (37661746152).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21804168408 is a wasteful number, since it uses less digits than its factorization.

21804168408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82591567 (or 82591563 counting only the distinct ones).

The product of its (nonzero) digits is 98304, while the sum is 42.

The spelling of 21804168408 in words is "twenty-one billion, eight hundred four million, one hundred sixty-eight thousand, four hundred eight".