1221121001021 has 4 divisors (see below), whose sum is σ = 1241817967200. Its totient is φ = 1200424034844.

The previous prime is 1221121000991. The next prime is 1221121001027. The reversal of 1221121001021 is 1201001211221.

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-1221121001021 is a prime.

It is a super-2 number, since 2×1221121001021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221121000987 and 1221121001005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221121001027) 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, 10348483001 + ... + 10348483118.

It is an arithmetic number, because the mean of its divisors is an integer number (310454491800).

Almost surely, 2^{1221121001021} is an apocalyptic number.

It is an amenable number.

1221121001021 is a deficient number, since it is larger than the sum of its proper divisors (20696966179).

1221121001021 is an equidigital number, since it uses as much as digits as its factorization.

1221121001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20696966178.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221121001021 its reverse (1201001211221), we get a palindrome (2422122212242).

The spelling of 1221121001021 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, one thousand, twenty-one".