21212022018 has 32 divisors (see below), whose sum is σ = 46339695360. Its totient is φ = 6419702160.

The previous prime is 21212021959. The next prime is 21212022019. The reversal of 21212022018 is 81022021212.

It is a junction number, because it is equal to n+sod(n) for n = 21212021985 and 21212022003.

It is not an unprimeable number, because it can be changed into a prime (21212022019) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152248 + ... + 256131.

It is an arithmetic number, because the mean of its divisors is an integer number (1448115480).

Almost surely, 2^21212022018 is an apocalyptic number.

21212022018 is an abundant number, since it is smaller than the sum of its proper divisors (25127673342).

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

21212022018 is a wasteful number, since it uses less digits than its factorization.

21212022018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409182.

The product of its (nonzero) digits is 256, while the sum is 21.

The spelling of 21212022018 in words is "twenty-one billion, two hundred twelve million, twenty-two thousand, eighteen".