221958 has 48 divisors (see below), whose sum is σ = 561600. Its totient is φ = 62640.

The previous prime is 221957. The next prime is 221987. The reversal of 221958 is 859122.

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 221958.

It is not an unprimeable number, because it can be changed into a prime (221951) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3733 + ... + 3791.

It is an arithmetic number, because the mean of its divisors is an integer number (11700).

2²²¹⁹⁵⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221958, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280800).

221958 is an abundant number, since it is smaller than the sum of its proper divisors (339642).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221958 is a wasteful number, since it uses less digits than its factorization.

221958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 94 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 221958 is about 471.1241874496. The cubic root of 221958 is about 60.5466707249.

The spelling of 221958 in words is "two hundred twenty-one thousand, nine hundred fifty-eight".