1221120121011 has 32 divisors (see below), whose sum is σ = 1880144179200. Its totient is φ = 690548608416.

The previous prime is 1221120121003. The next prime is 1221120121031. The reversal of 1221120121011 is 1101210211221.

It is a happy number.

It is not a de Polignac number, because 1221120121011 - 2³ = 1221120121003 is a prime.

It is a super-2 number, since 2×1221120121011² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221120121031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29140 + ... + 1563038.

It is an arithmetic number, because the mean of its divisors is an integer number (58754505600).

Almost surely, 2^{1221120121011} is an apocalyptic number.

1221120121011 is a deficient number, since it is larger than the sum of its proper divisors (659024058189).

1221120121011 is a wasteful number, since it uses less digits than its factorization.

1221120121011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534303.

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

Adding to 1221120121011 its reverse (1101210211221), we get a palindrome (2322330332232).

The spelling of 1221120121011 in words is "one trillion, two hundred twenty-one billion, one hundred twenty million, one hundred twenty-one thousand, eleven".