1220121001221 has 4 divisors (see below), whose sum is σ = 1626828001632. Its totient is φ = 813414000812.

The previous prime is 1220121001213. The next prime is 1220121001243. The reversal of 1220121001221 is 1221001210221.

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 1220121001221 - 2³ = 1220121001213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1220121001221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220121001291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203353500201 + ... + 203353500206.

It is an arithmetic number, because the mean of its divisors is an integer number (406707000408).

Almost surely, 2^{1220121001221} is an apocalyptic number.

It is an amenable number.

1220121001221 is a deficient number, since it is larger than the sum of its proper divisors (406707000411).

1220121001221 is an equidigital number, since it uses as much as digits as its factorization.

1220121001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406707000410.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1220121001221 its reverse (1221001210221), we get a palindrome (2441122211442).

The spelling of 1220121001221 in words is "one trillion, two hundred twenty billion, one hundred twenty-one million, one thousand, two hundred twenty-one".