21807855798 has 8 divisors (see below), whose sum is σ = 43615711608. Its totient is φ = 7269285264.

The previous prime is 21807855793. The next prime is 21807855809. The reversal of 21807855798 is 89755870812.

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

21807855798 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21807855793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1817321311 + ... + 1817321322.

It is an arithmetic number, because the mean of its divisors is an integer number (5451963951).

Almost surely, 2^21807855798 is an apocalyptic number.

21807855798 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21807855798 is a wasteful number, since it uses less digits than its factorization.

21807855798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3634642638.

The product of its (nonzero) digits is 11289600, while the sum is 60.

The spelling of 21807855798 in words is "twenty-one billion, eight hundred seven million, eight hundred fifty-five thousand, seven hundred ninety-eight".