221111999 has 8 divisors (see below), whose sum is σ = 225173520. Its totient is φ = 217061056.

The previous prime is 221111983. The next prime is 221112019. The reversal of 221111999 is 999111122.

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

It is a cyclic number.

It is not a de Polignac number, because 221111999 - 2⁴ = 221111983 is a prime.

It is a super-2 number, since 2×221111999² = 97781032203552002, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48377 + ... + 52749.

It is an arithmetic number, because the mean of its divisors is an integer number (28146690).

Almost surely, 2^221111999 is an apocalyptic number.

221111999 is a deficient number, since it is larger than the sum of its proper divisors (4061521).

221111999 is an equidigital number, since it uses as much as digits as its factorization.

221111999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5289.

The product of its digits is 2916, while the sum is 35.

The square root of 221111999 is about 14869.8352041978. The cubic root of 221111999 is about 604.6964750283.

The spelling of 221111999 in words is "two hundred twenty-one million, one hundred eleven thousand, nine hundred ninety-nine".