221438 has 8 divisors (see below), whose sum is σ = 379632. Its totient is φ = 94896.

The previous prime is 221413. The next prime is 221447. The reversal of 221438 is 834122.

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

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 221438.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7895 + ... + 7922.

It is an arithmetic number, because the mean of its divisors is an integer number (47454).

2²²¹⁴³⁸ is an apocalyptic number.

221438 is a deficient number, since it is larger than the sum of its proper divisors (158194).

221438 is a wasteful number, since it uses less digits than its factorization.

221438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15826.

The product of its digits is 384, while the sum is 20.

The square root of 221438 is about 470.5719923667. The cubic root of 221438 is about 60.4993511303.

The spelling of 221438 in words is "two hundred twenty-one thousand, four hundred thirty-eight".