1221122012021 has 4 divisors (see below), whose sum is σ = 1221133232832. Its totient is φ = 1221110791212.

The previous prime is 1221122012009. The next prime is 1221122012041. The reversal of 1221122012021 is 1202102211221.

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 a de Polignac number, because none of the positive numbers 2^k-1221122012021 is a prime.

It is a super-2 number, since 2×1221122012021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221122012041) 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, 5445551 + ... + 5665356.

It is an arithmetic number, because the mean of its divisors is an integer number (305283308208).

Almost surely, 2^{1221122012021} is an apocalyptic number.

It is an amenable number.

1221122012021 is a deficient number, since it is larger than the sum of its proper divisors (11220811).

1221122012021 is a wasteful number, since it uses less digits than its factorization.

1221122012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11220810.

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

Adding to 1221122012021 its reverse (1202102211221), we get a palindrome (2423224223242).

The spelling of 1221122012021 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, twelve thousand, twenty-one".