1221222110021 has 4 divisors (see below), whose sum is σ = 1232425982700. Its totient is φ = 1210018237344.

The previous prime is 1221222110011. The next prime is 1221222110027. The reversal of 1221222110021 is 1200112221221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 745969053025 + 475253056996 = 863695^2 + 689386^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221222110021 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 (1221222110027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5601936176 + ... + 5601936393.

It is an arithmetic number, because the mean of its divisors is an integer number (308106495675).

Almost surely, 2^{1221222110021} is an apocalyptic number.

It is an amenable number.

1221222110021 is a deficient number, since it is larger than the sum of its proper divisors (11203872679).

1221222110021 is a wasteful number, since it uses less digits than its factorization.

1221222110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11203872678.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1221222110021 its reverse (1200112221221), we get a palindrome (2421334331242).

The spelling of 1221222110021 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two million, one hundred ten thousand, twenty-one".