2111222021221 has 16 divisors (see below), whose sum is σ = 2139484762800. Its totient is φ = 2083138560000.

The previous prime is 2111222021197. The next prime is 2111222021299. The reversal of 2111222021221 is 1221202221112.

It can be written as a sum of positive squares in 8 ways, for example, as 700795008225 + 1410427012996 = 837135^2 + 1187614^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111222021221 - 2⁷ = 2111222021093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111222024221) 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, 26228925 + ... + 26309293.

It is an arithmetic number, because the mean of its divisors is an integer number (133717797675).

Almost surely, 2^{2111222021221} is an apocalyptic number.

It is an amenable number.

2111222021221 is a deficient number, since it is larger than the sum of its proper divisors (28262741579).

2111222021221 is a wasteful number, since it uses less digits than its factorization.

2111222021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81480.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 2111222021221 its reverse (1221202221112), we get a palindrome (3332424242333).

The spelling of 2111222021221 in words is "two trillion, one hundred eleven billion, two hundred twenty-two million, twenty-one thousand, two hundred twenty-one".