111311212221 has 48 divisors (see below), whose sum is σ = 177569765568. Its totient is φ = 66630412800.

The previous prime is 111311212219. The next prime is 111311212223. The reversal of 111311212221 is 122212113111.

It is a happy number.

111311212221 is a `hidden beast` number, since 111 + 311 + 21 + 2 + 221 = 666.

It is an interprime number because it is at equal distance from previous prime (111311212219) and next prime (111311212223).

It is not a de Polignac number, because 111311212221 - 2¹ = 111311212219 is a prime.

It is a super-2 number, since 2×111311212221² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 111311212194 and 111311212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111311212223) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3554251 + ... + 3585431.

It is an arithmetic number, because the mean of its divisors is an integer number (3699370116).

Almost surely, 2^111311212221 is an apocalyptic number.

111311212221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111311212221 is a deficient number, since it is larger than the sum of its proper divisors (66258553347).

111311212221 is a wasteful number, since it uses less digits than its factorization.

111311212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31642 (or 31639 counting only the distinct ones).

The product of its digits is 48, while the sum is 18.

Adding to 111311212221 its reverse (122212113111), we get a palindrome (233523325332).

The spelling of 111311212221 in words is "one hundred eleven billion, three hundred eleven million, two hundred twelve thousand, two hundred twenty-one".