1211221111012 has 24 divisors (see below), whose sum is σ = 2312492021280. Its totient is φ = 550516762560.

The previous prime is 1211221110919. The next prime is 1211221111049. The reversal of 1211221111012 is 2101111221121.

It is a super-2 number, since 2×1211221111012² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 312438 + ... + 1587469.

It is an arithmetic number, because the mean of its divisors is an integer number (96353834220).

Almost surely, 2^{1211221111012} is an apocalyptic number.

It is an amenable number.

1211221111012 is a deficient number, since it is larger than the sum of its proper divisors (1101270910268).

1211221111012 is a wasteful number, since it uses less digits than its factorization.

1211221111012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1914411 (or 1914409 counting only the distinct ones).

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

Adding to 1211221111012 its reverse (2101111221121), we get a palindrome (3312332332133).

The spelling of 1211221111012 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, twelve".