1021112111221 has 16 divisors (see below), whose sum is σ = 1035085463280. Its totient is φ = 1007197396480.

The previous prime is 1021112111207. The next prime is 1021112111249. The reversal of 1021112111221 is 1221112111201.

It can be written as a sum of positive squares in 8 ways, for example, as 105475552900 + 915636558321 = 324770^2 + 956889^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021112111221 - 2⁵ = 1021112111189 is a prime.

It is a super-2 number, since 2×1021112111221² (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 = 1021112111195 and 1021112111204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021112111251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64730091 + ... + 64745863.

It is an arithmetic number, because the mean of its divisors is an integer number (64692841455).

Almost surely, 2^{1021112111221} is an apocalyptic number.

It is an amenable number.

1021112111221 is a deficient number, since it is larger than the sum of its proper divisors (13973352059).

1021112111221 is an equidigital number, since it uses as much as digits as its factorization.

1021112111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17576.

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

Adding to 1021112111221 its reverse (1221112111201), we get a palindrome (2242224222422).

The spelling of 1021112111221 in words is "one trillion, twenty-one billion, one hundred twelve million, one hundred eleven thousand, two hundred twenty-one".