221557 has 8 divisors (see below), whose sum is σ = 261632. Its totient is φ = 183600.

The previous prime is 221549. The next prime is 221567. The reversal of 221557 is 755122.

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

It is a cyclic number.

It is not a de Polignac number, because 221557 - 2³ = 221549 is a prime.

221557 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 294 + ... + 727.

It is an arithmetic number, because the mean of its divisors is an integer number (32704).

2²²¹⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

221557 is a deficient number, since it is larger than the sum of its proper divisors (40075).

221557 is a wasteful number, since it uses less digits than its factorization.

221557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1059.

The product of its digits is 700, while the sum is 22.

The square root of 221557 is about 470.6984172482. The cubic root of 221557 is about 60.5101865688.

Adding to 221557 its reverse (755122), we get a palindrome (976679).

The spelling of 221557 in words is "two hundred twenty-one thousand, five hundred fifty-seven".