1220221100021 has 72 divisors (see below), whose sum is σ = 1643340041280. Its totient is φ = 900223632000.

The previous prime is 1220221100009. The next prime is 1220221100027. The reversal of 1220221100021 is 1200011220221.

It is not a de Polignac number, because 1220221100021 - 2¹⁰ = 1220221098997 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1220221099969 and 1220221100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220221100027) 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 71 ways as a sum of consecutive naturals, for example, 314407001 + ... + 314410881.

It is an arithmetic number, because the mean of its divisors is an integer number (22824167240).

Almost surely, 2^{1220221100021} is an apocalyptic number.

1220221100021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220221100021 is a deficient number, since it is larger than the sum of its proper divisors (423118941259).

1220221100021 is a wasteful number, since it uses less digits than its factorization.

1220221100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6727 (or 6709 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1220221100021 its reverse (1200011220221), we get a palindrome (2420232320242).

The spelling of 1220221100021 in words is "one trillion, two hundred twenty billion, two hundred twenty-one million, one hundred thousand, twenty-one".