221220111 has 8 divisors (see below), whose sum is σ = 337097344. Its totient is φ = 126411480.

The previous prime is 221220107. The next prime is 221220119. The reversal of 221220111 is 111022122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221220111 - 2² = 221220107 is a prime.

It is a super-3 number, since 3×221220111³ (a number of 26 digits) contains 333 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 (221220119) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5267125 + ... + 5267166.

It is an arithmetic number, because the mean of its divisors is an integer number (42137168).

Almost surely, 2^221220111 is an apocalyptic number.

221220111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

221220111 is a deficient number, since it is larger than the sum of its proper divisors (115877233).

221220111 is a wasteful number, since it uses less digits than its factorization.

221220111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10534301.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 221220111 is about 14873.4700389654. The cubic root of 221220111 is about 604.7950137682.

Adding to 221220111 its reverse (111022122), we get a palindrome (332242233).

The spelling of 221220111 in words is "two hundred twenty-one million, two hundred twenty thousand, one hundred eleven".