1221201211011 has 8 divisors (see below), whose sum is σ = 1644076711680. Its totient is φ = 806229925512.

The previous prime is 1221201210991. The next prime is 1221201211037. The reversal of 1221201211011 is 1101121021221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221201211011 - 2²³ = 1221192822403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221201211051) 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 7 ways as a sum of consecutive naturals, for example, 1976053431 + ... + 1976054048.

It is an arithmetic number, because the mean of its divisors is an integer number (205509588960).

Almost surely, 2^{1221201211011} is an apocalyptic number.

1221201211011 is a deficient number, since it is larger than the sum of its proper divisors (422875500669).

1221201211011 is a wasteful number, since it uses less digits than its factorization.

1221201211011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3952107585.

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

Adding to 1221201211011 its reverse (1101121021221), we get a palindrome (2322322232232).

The spelling of 1221201211011 in words is "one trillion, two hundred twenty-one billion, two hundred one million, two hundred eleven thousand, eleven".