221390 has 24 divisors (see below), whose sum is σ = 434808. Its totient is φ = 81120.

The previous prime is 221327. The next prime is 221393. The reversal of 221390 is 93122.

221390 = 38² + 39² + ... + 89².

221390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221390.

It is not an unprimeable number, because it can be changed into a prime (221393) by changing a digit.

221390 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1625 + ... + 1755.

It is an arithmetic number, because the mean of its divisors is an integer number (18117).

2²²¹³⁹⁰ is an apocalyptic number.

221390 is a deficient number, since it is larger than the sum of its proper divisors (213418).

221390 is a wasteful number, since it uses less digits than its factorization.

221390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 221390 is about 470.5209878422. The cubic root of 221390 is about 60.4949794345.

The spelling of 221390 in words is "two hundred twenty-one thousand, three hundred ninety".