221201221212 has 18 divisors (see below), whose sum is σ = 559147531488. Its totient is φ = 73733740392.

The previous prime is 221201221183. The next prime is 221201221243. The reversal of 221201221212 is 212122102122.

It is a happy number.

221201221212 is a `hidden beast` number, since 221 + 201 + 221 + 21 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3072239148 + ... + 3072239219.

Almost surely, 2^221201221212 is an apocalyptic number.

It is an amenable number.

221201221212 is an abundant number, since it is smaller than the sum of its proper divisors (337946310276).

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

221201221212 is a wasteful number, since it uses less digits than its factorization.

221201221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6144478377 (or 6144478372 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221201221212 its reverse (212122102122), we get a palindrome (433323323334).

The spelling of 221201221212 in words is "two hundred twenty-one billion, two hundred one million, two hundred twenty-one thousand, two hundred twelve".