1000121111221 has 4 divisors (see below), whose sum is σ = 1001666894112. Its totient is φ = 998575328332.

The previous prime is 1000121111219. The next prime is 1000121111243. The reversal of 1000121111221 is 1221111210001.

It is a happy number.

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 1000121111221 - 2¹ = 1000121111219 is a prime.

It is a super-2 number, since 2×1000121111221² (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 (1000121111281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 772890475 + ... + 772891768.

It is an arithmetic number, because the mean of its divisors is an integer number (250416723528).

Almost surely, 2^{1000121111221} is an apocalyptic number.

It is an amenable number.

1000121111221 is a deficient number, since it is larger than the sum of its proper divisors (1545782891).

1000121111221 is an equidigital number, since it uses as much as digits as its factorization.

1000121111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1545782890.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1000121111221 its reverse (1221111210001), we get a palindrome (2221232321222).

The spelling of 1000121111221 in words is "one trillion, one hundred twenty-one million, one hundred eleven thousand, two hundred twenty-one".