221021211212 has 24 divisors (see below), whose sum is σ = 388717208880. Its totient is φ = 109959413760.

The previous prime is 221021211211. The next prime is 221021211227. The reversal of 221021211212 is 212112120122.

It is not an unprimeable number, because it can be changed into a prime (221021211211) 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, 3589388 + ... + 3650444.

It is an arithmetic number, because the mean of its divisors is an integer number (16196550370).

Almost surely, 2^221021211212 is an apocalyptic number.

It is an amenable number.

221021211212 is a deficient number, since it is larger than the sum of its proper divisors (167695997668).

221021211212 is a wasteful number, since it uses less digits than its factorization.

221021211212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65561 (or 65559 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221021211212 its reverse (212112120122), we get a palindrome (433133331334).

The spelling of 221021211212 in words is "two hundred twenty-one billion, twenty-one million, two hundred eleven thousand, two hundred twelve".