221648 has 20 divisors (see below), whose sum is σ = 491040. Its totient is φ = 94944.

The previous prime is 221623. The next prime is 221653. The reversal of 221648 is 846122.

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 221648.

It is an unprimeable number.

221648 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 3 ways as a sum of consecutive naturals, for example, 878 + ... + 1101.

It is an arithmetic number, because the mean of its divisors is an integer number (24552).

2²²¹⁶⁴⁸ is an apocalyptic number.

221648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

221648 is an abundant number, since it is smaller than the sum of its proper divisors (269392).

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

221648 is a wasteful number, since it uses less digits than its factorization.

221648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1994 (or 1988 counting only the distinct ones).

The product of its digits is 768, while the sum is 23.

The square root of 221648 is about 470.7950721917. The cubic root of 221648 is about 60.5184698748.

The spelling of 221648 in words is "two hundred twenty-one thousand, six hundred forty-eight".