221212212012 has 36 divisors (see below), whose sum is σ = 610009434216. Its totient is φ = 67034003520.

The previous prime is 221212211963. The next prime is 221212212031. The reversal of 221212212012 is 210212212122.

It is a happy number.

221212212012 is a `hidden beast` number, since 221 + 21 + 221 + 201 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 279307953 + ... + 279308744.

It is an arithmetic number, because the mean of its divisors is an integer number (16944706506).

Almost surely, 2^221212212012 is an apocalyptic number.

221212212012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

221212212012 is an abundant number, since it is smaller than the sum of its proper divisors (388797222204).

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

221212212012 is a wasteful number, since it uses less digits than its factorization.

221212212012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558616718 (or 558616713 counting only the distinct ones).

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

Adding to 221212212012 its reverse (210212212122), we get a palindrome (431424424134).

The spelling of 221212212012 in words is "two hundred twenty-one billion, two hundred twelve million, two hundred twelve thousand, twelve".