21012102218 has 16 divisors (see below), whose sum is σ = 32309323200. Its totient is φ = 10242684000.

The previous prime is 21012102211. The next prime is 21012102239. The reversal of 21012102218 is 81220121012.

It is a self number, because there is not a number n which added to its sum of digits gives 21012102218.

It is not an unprimeable number, because it can be changed into a prime (21012102211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30683 + ... + 207281.

It is an arithmetic number, because the mean of its divisors is an integer number (2019332700).

Almost surely, 2^21012102218 is an apocalyptic number.

21012102218 is a deficient number, since it is larger than the sum of its proper divisors (11297220982).

21012102218 is a wasteful number, since it uses less digits than its factorization.

21012102218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178093.

The product of its (nonzero) digits is 128, while the sum is 20.

The spelling of 21012102218 in words is "twenty-one billion, twelve million, one hundred two thousand, two hundred eighteen".