21818222028 has 36 divisors (see below), whose sum is σ = 55720199080. Its totient is φ = 7197762816.

The previous prime is 21818222021. The next prime is 21818222033. The reversal of 21818222028 is 82022281812.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21818221983 and 21818222001.

It is not an unprimeable number, because it can be changed into a prime (21818222021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3120538 + ... + 3127521.

Almost surely, 2^21818222028 is an apocalyptic number.

It is an amenable number.

21818222028 is an abundant number, since it is smaller than the sum of its proper divisors (33901977052).

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

21818222028 is a wasteful number, since it uses less digits than its factorization.

21818222028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6248166 (or 6248161 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 36.

The spelling of 21818222028 in words is "twenty-one billion, eight hundred eighteen million, two hundred twenty-two thousand, twenty-eight".