21016220218 has 16 divisors (see below), whose sum is σ = 36031469184. Its totient is φ = 9006035760.

The previous prime is 21016220213. The next prime is 21016220227. The reversal of 21016220218 is 81202261012.

It is a junction number, because it is equal to n+sod(n) for n = 21016220192 and 21016220201.

It is not an unprimeable number, because it can be changed into a prime (21016220213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76908 + ... + 218968.

It is an arithmetic number, because the mean of its divisors is an integer number (2251966824).

Almost surely, 2^21016220218 is an apocalyptic number.

21016220218 is a deficient number, since it is larger than the sum of its proper divisors (15015248966).

21016220218 is a wasteful number, since it uses less digits than its factorization.

21016220218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152637.

The product of its (nonzero) digits is 768, while the sum is 25.

The spelling of 21016220218 in words is "twenty-one billion, sixteen million, two hundred twenty thousand, two hundred eighteen".