11111021212221 has 24 divisors (see below), whose sum is σ = 18732258664704. Its totient is φ = 6214066572960.

The previous prime is 11111021212219. The next prime is 11111021212229. The reversal of 11111021212221 is 12221212011111.

It is a happy number.

11111021212221 is a `hidden beast` number, since 111 + 110 + 212 + 12 + 221 = 666.

It is not a de Polignac number, because 11111021212221 - 2¹ = 11111021212219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11111021212194 and 11111021212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111021212229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1876224870 + ... + 1876230791.

It is an arithmetic number, because the mean of its divisors is an integer number (780510777696).

Almost surely, 2^{11111021212221} is an apocalyptic number.

It is an amenable number.

11111021212221 is a deficient number, since it is larger than the sum of its proper divisors (7621237452483).

11111021212221 is a wasteful number, since it uses less digits than its factorization.

11111021212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3752455721 (or 3752455718 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 11111021212221 its reverse (12221212011111), we get a palindrome (23332233223332).

The spelling of 11111021212221 in words is "eleven trillion, one hundred eleven billion, twenty-one million, two hundred twelve thousand, two hundred twenty-one".