221718889 has 4 divisors (see below), whose sum is σ = 253393024. Its totient is φ = 190044756.

The previous prime is 221718883. The next prime is 221718901. The reversal of 221718889 is 988817122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221718889 - 2⁹ = 221718377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221718883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15837057 + ... + 15837070.

It is an arithmetic number, because the mean of its divisors is an integer number (63348256).

Almost surely, 2^221718889 is an apocalyptic number.

It is an amenable number.

221718889 is a deficient number, since it is larger than the sum of its proper divisors (31674135).

221718889 is an equidigital number, since it uses as much as digits as its factorization.

221718889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31674134.

The product of its digits is 129024, while the sum is 46.

The square root of 221718889 is about 14890.2279700480. The cubic root of 221718889 is about 605.2492099928.

The spelling of 221718889 in words is "two hundred twenty-one million, seven hundred eighteen thousand, eight hundred eighty-nine".