1221011221212 has 72 divisors (see below), whose sum is σ = 3201247594272. Its totient is φ = 392082768000.

The previous prime is 1221011221193. The next prime is 1221011221247. The reversal of 1221011221212 is 2121221101221.

1221011221212 is a `hidden beast` number, since 1 + 221 + 0 + 11 + 221 + 212 = 666.

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 23 ways as a sum of consecutive naturals, for example, 4403464 + ... + 4672527.

Almost surely, 2^{1221011221212} is an apocalyptic number.

1221011221212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221011221212 is an abundant number, since it is smaller than the sum of its proper divisors (1980236373060).

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

1221011221212 is a wasteful number, since it uses less digits than its factorization.

1221011221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9076139 (or 9076134 counting only the distinct ones).

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

Adding to 1221011221212 its reverse (2121221101221), we get a palindrome (3342232322433).

The spelling of 1221011221212 in words is "one trillion, two hundred twenty-one billion, eleven million, two hundred twenty-one thousand, two hundred twelve".