1221112222021 has 4 divisors (see below), whose sum is σ = 1221228540000. Its totient is φ = 1220995904044.

The previous prime is 1221112222003. The next prime is 1221112222039. The reversal of 1221112222021 is 1202222111221.

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 an interprime number because it is at equal distance from previous prime (1221112222003) and next prime (1221112222039).

It is a cyclic number.

It is not a de Polignac number, because 1221112222021 - 2⁷ = 1221112221893 is a prime.

It is a super-2 number, since 2×1221112222021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221112222021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221112222081) 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, 58143241 + ... + 58164238.

It is an arithmetic number, because the mean of its divisors is an integer number (305307135000).

Almost surely, 2^{1221112222021} is an apocalyptic number.

It is an amenable number.

1221112222021 is a deficient number, since it is larger than the sum of its proper divisors (116317979).

1221112222021 is a wasteful number, since it uses less digits than its factorization.

1221112222021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116317978.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1221112222021 its reverse (1202222111221), we get a palindrome (2423334333242).

The spelling of 1221112222021 in words is "one trillion, two hundred twenty-one billion, one hundred twelve million, two hundred twenty-two thousand, twenty-one".