21663822858 has 16 divisors (see below), whose sum is σ = 43330114080. Its totient is φ = 7220862896.

The previous prime is 21663822799. The next prime is 21663822883. The reversal of 21663822858 is 85822836612.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21663822858.

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, 23116 + ... + 209432.

It is an arithmetic number, because the mean of its divisors is an integer number (2708132130).

Almost surely, 2^21663822858 is an apocalyptic number.

21663822858 is an abundant number, since it is smaller than the sum of its proper divisors (21666291222).

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

21663822858 is a wasteful number, since it uses less digits than its factorization.

21663822858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205701.

The product of its digits is 2211840, while the sum is 51.

The spelling of 21663822858 in words is "twenty-one billion, six hundred sixty-three million, eight hundred twenty-two thousand, eight hundred fifty-eight".