221572 has 12 divisors (see below), whose sum is σ = 417676. Its totient is φ = 102240.

The previous prime is 221567. The next prime is 221581. The reversal of 221572 is 275122.

221572 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 133956 + 87616 = 366^2 + 296^2 .

It is a hoax number, since the sum of its digits (19) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

221572 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2079 + ... + 2182.

2²²¹⁵⁷² is an apocalyptic number.

It is an amenable number.

221572 is a deficient number, since it is larger than the sum of its proper divisors (196104).

221572 is a wasteful number, since it uses less digits than its factorization.

221572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4278 (or 4276 counting only the distinct ones).

The product of its digits is 280, while the sum is 19.

The square root of 221572 is about 470.7143507479. The cubic root of 221572 is about 60.5115521050.

Adding to 221572 its reverse (275122), we get a palindrome (496694).

The spelling of 221572 in words is "two hundred twenty-one thousand, five hundred seventy-two".