1221000222021 has 4 divisors (see below), whose sum is σ = 1628000296032. Its totient is φ = 814000148012.

The previous prime is 1221000222017. The next prime is 1221000222031. The reversal of 1221000222021 is 1202220001221.

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 1221000222021 - 2² = 1221000222017 is a prime.

It is a super-3 number, since 3×1221000222021³ (a number of 37 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000222031) 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, 203500037001 + ... + 203500037006.

It is an arithmetic number, because the mean of its divisors is an integer number (407000074008).

Almost surely, 2^{1221000222021} is an apocalyptic number.

It is an amenable number.

1221000222021 is a deficient number, since it is larger than the sum of its proper divisors (407000074011).

1221000222021 is an equidigital number, since it uses as much as digits as its factorization.

1221000222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407000074010.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 1221000222021 its reverse (1202220001221), we get a palindrome (2423220223242).

The spelling of 1221000222021 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two thousand, twenty-one".