111211111220221 has 16 divisors (see below), whose sum is σ = 116706367814400. Its totient is φ = 105771043762560.

The previous prime is 111211111220201. The next prime is 111211111220233. The reversal of 111211111220221 is 122022111112111.

It is a cyclic number.

It is not a de Polignac number, because 111211111220221 - 2²³ = 111211102831613 is a prime.

It is a super-2 number, since 2×111211111220221² (a number of 29 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 (111211111220201) 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, 23651721 + ... + 27961153.

It is an arithmetic number, because the mean of its divisors is an integer number (7294147988400).

Almost surely, 2^{111211111220221} is an apocalyptic number.

It is an amenable number.

111211111220221 is a deficient number, since it is larger than the sum of its proper divisors (5495256594179).

111211111220221 is a wasteful number, since it uses less digits than its factorization.

111211111220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4315836.

The product of its (nonzero) digits is 32, while the sum is 19.

Adding to 111211111220221 its reverse (122022111112111), we get a palindrome (233233222332332).

The spelling of 111211111220221 in words is "one hundred eleven trillion, two hundred eleven billion, one hundred eleven million, two hundred twenty thousand, two hundred twenty-one".