1221212011101 has 16 divisors (see below), whose sum is σ = 1724309452800. Its totient is φ = 766141590528.

The previous prime is 1221212011057. The next prime is 1221212011111. The reversal of 1221212011101 is 1011102121221.

It is a happy number.

It is not a de Polignac number, because 1221212011101 - 2¹⁰ = 1221212010077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221212011111) 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, 1341916 + ... + 2059893.

It is an arithmetic number, because the mean of its divisors is an integer number (107769340800).

Almost surely, 2^{1221212011101} is an apocalyptic number.

It is an amenable number.

1221212011101 is a deficient number, since it is larger than the sum of its proper divisors (503097441699).

1221212011101 is a wasteful number, since it uses less digits than its factorization.

1221212011101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3408868.

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

Adding to 1221212011101 its reverse (1011102121221), we get a palindrome (2232314132322).

The spelling of 1221212011101 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, eleven thousand, one hundred one".