1221010111212 has 48 divisors (see below), whose sum is σ = 2926666455552. Its totient is φ = 395916361920.

The previous prime is 1221010111177. The next prime is 1221010111219. The reversal of 1221010111212 is 2121110101221.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1221010111191 and 1221010111200.

It is not an unprimeable number, because it can be changed into a prime (1221010111219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1738903 + ... + 2337905.

It is an arithmetic number, because the mean of its divisors is an integer number (60972217824).

Almost surely, 2^{1221010111212} is an apocalyptic number.

1221010111212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221010111212 is an abundant number, since it is smaller than the sum of its proper divisors (1705656344340).

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

1221010111212 is a wasteful number, since it uses less digits than its factorization.

1221010111212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603638 (or 603636 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221010111212 its reverse (2121110101221), we get a palindrome (3342120212433).

Subtracting 1221010111212 from its reverse (2121110101221), we obtain a palindrome (900099990009).

The spelling of 1221010111212 in words is "one trillion, two hundred twenty-one billion, ten million, one hundred eleven thousand, two hundred twelve".