221965 has 8 divisors (see below), whose sum is σ = 269568. Its totient is φ = 175440.

The previous prime is 221957. The next prime is 221987. The reversal of 221965 is 569122.

221965 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 221965 - 2³ = 221957 is a prime.

It is a super-2 number, since 2×221965² = 98536922450, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 300 + ... + 730.

It is an arithmetic number, because the mean of its divisors is an integer number (33696).

2²²¹⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

221965 is a deficient number, since it is larger than the sum of its proper divisors (47603).

221965 is a wasteful number, since it uses less digits than its factorization.

221965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539.

The product of its digits is 1080, while the sum is 25.

The square root of 221965 is about 471.1316164301. The cubic root of 221965 is about 60.5473072151.

It can be divided in two parts, 22196 and 5, that added together give a square (22201 = 149²).

The spelling of 221965 in words is "two hundred twenty-one thousand, nine hundred sixty-five".