1221100011021 has 32 divisors (see below), whose sum is σ = 1962390924288. Its totient is φ = 666243818240.

The previous prime is 1221100011007. The next prime is 1221100011031. The reversal of 1221100011021 is 1201100011221.

It is not a de Polignac number, because 1221100011021 - 2²⁹ = 1220563140109 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1221100010988 and 1221100011006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221100011031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47305551 + ... + 47331356.

It is an arithmetic number, because the mean of its divisors is an integer number (61324716384).

Almost surely, 2^{1221100011021} is an apocalyptic number.

1221100011021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221100011021 is a deficient number, since it is larger than the sum of its proper divisors (741290913267).

1221100011021 is a wasteful number, since it uses less digits than its factorization.

1221100011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94636961.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1221100011021 its reverse (1201100011221), we get a palindrome (2422200022242).

The spelling of 1221100011021 in words is "one trillion, two hundred twenty-one billion, one hundred million, eleven thousand, twenty-one".