21812806016 has 16 divisors (see below), whose sum is σ = 43455199740. Its totient is φ = 10906402944.

The previous prime is 21812806009. The next prime is 21812806027. The reversal of 21812806016 is 61060821812.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85206146 + ... + 85206401.

Almost surely, 2^21812806016 is an apocalyptic number.

It is an amenable number.

21812806016 is a deficient number, since it is larger than the sum of its proper divisors (21642393724).

21812806016 is an equidigital number, since it uses as much as digits as its factorization.

21812806016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170412561 (or 170412549 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 35.

The spelling of 21812806016 in words is "twenty-one billion, eight hundred twelve million, eight hundred six thousand, sixteen".