21810864846 has 16 divisors (see below), whose sum is σ = 43808950224. Its totient is φ = 7239084864.

The previous prime is 21810864743. The next prime is 21810864847. The reversal of 21810864846 is 64846801812.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21810864795 and 21810864804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21810864847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7799341 + ... + 7802136.

It is an arithmetic number, because the mean of its divisors is an integer number (2738059389).

Almost surely, 2^21810864846 is an apocalyptic number.

21810864846 is an abundant number, since it is smaller than the sum of its proper divisors (21998085378).

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

21810864846 is a wasteful number, since it uses less digits than its factorization.

21810864846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15601715.

The product of its (nonzero) digits is 589824, while the sum is 48.

The spelling of 21810864846 in words is "twenty-one billion, eight hundred ten million, eight hundred sixty-four thousand, eight hundred forty-six".