1220021000221 has 4 divisors (see below), whose sum is σ = 1220023245952. Its totient is φ = 1220018754492.

The previous prime is 1220021000207. The next prime is 1220021000251. The reversal of 1220021000221 is 1220001200221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1220021000221 - 2¹⁵ = 1220020967453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220021000251) 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 3 ways as a sum of consecutive naturals, for example, 258430 + ... + 1583296.

It is an arithmetic number, because the mean of its divisors is an integer number (305005811488).

Almost surely, 2^{1220021000221} is an apocalyptic number.

It is an amenable number.

1220021000221 is a deficient number, since it is larger than the sum of its proper divisors (2245731).

1220021000221 is an equidigital number, since it uses as much as digits as its factorization.

1220021000221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2245730.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 1220021000221 its reverse (1220001200221), we get a palindrome (2440022200442).

The spelling of 1220021000221 in words is "one trillion, two hundred twenty billion, twenty-one million, two hundred twenty-one", and thus it is an aban number.