1011121221221 has 4 divisors (see below), whose sum is σ = 1055083013472. Its totient is φ = 967159428972.

The previous prime is 1011121221199. The next prime is 1011121221337. The reversal of 1011121221221 is 1221221211101.

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 1011121221221 - 2⁶ = 1011121221157 is a prime.

It is a super-2 number, since 2×1011121221221² (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 1011121221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011121226221) 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, 21980896091 + ... + 21980896136.

It is an arithmetic number, because the mean of its divisors is an integer number (263770753368).

Almost surely, 2^{1011121221221} is an apocalyptic number.

It is an amenable number.

1011121221221 is a deficient number, since it is larger than the sum of its proper divisors (43961792251).

1011121221221 is an equidigital number, since it uses as much as digits as its factorization.

1011121221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43961792250.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1011121221221 its reverse (1221221211101), we get a palindrome (2232342432322).

The spelling of 1011121221221 in words is "one trillion, eleven billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".