221211211212 has 72 divisors (see below), whose sum is σ = 566187148800. Its totient is φ = 72815923200.

The previous prime is 221211211129. The next prime is 221211211321. The reversal of 221211211212 is 212112112122.

221211211212 is a `hidden beast` number, since 221 + 21 + 1 + 211 + 212 = 666.

221211211212 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1313164 + ... + 1472012.

It is an arithmetic number, because the mean of its divisors is an integer number (7863710400).

Almost surely, 2^221211211212 is an apocalyptic number.

It is an amenable number.

221211211212 is an abundant number, since it is smaller than the sum of its proper divisors (344975937588).

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

221211211212 is a wasteful number, since it uses less digits than its factorization.

221211211212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159343 (or 159338 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 221211211212 its reverse (212112112122), we get a palindrome (433323323334).

It can be divided in two parts, 2 and 21211211212, that multiplied together give a palindrome (42422422424).

The spelling of 221211211212 in words is "two hundred twenty-one billion, two hundred eleven million, two hundred eleven thousand, two hundred twelve".