221612111217 has 64 divisors (see below), whose sum is σ = 388002908160. Its totient is φ = 122391352512.

The previous prime is 221612111207. The next prime is 221612111243. The reversal of 221612111217 is 712111216122.

221612111217 is a `hidden beast` number, since 2 + 21 + 612 + 1 + 1 + 1 + 21 + 7 = 666.

It is not a de Polignac number, because 221612111217 - 2⁸ = 221612110961 is a prime.

It is a super-2 number, since 2×221612111217² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (221612111207) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 506038 + ... + 836240.

It is an arithmetic number, because the mean of its divisors is an integer number (6062545440).

Almost surely, 2^221612111217 is an apocalyptic number.

221612111217 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

221612111217 is a deficient number, since it is larger than the sum of its proper divisors (166390796943).

221612111217 is a wasteful number, since it uses less digits than its factorization.

221612111217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330339 (or 330333 counting only the distinct ones).

The product of its digits is 672, while the sum is 27.

Adding to 221612111217 its reverse (712111216122), we get a palindrome (933723327339).

The spelling of 221612111217 in words is "two hundred twenty-one billion, six hundred twelve million, one hundred eleven thousand, two hundred seventeen".