221608 has 8 divisors (see below), whose sum is σ = 415530. Its totient is φ = 110800.

The previous prime is 221603. The next prime is 221621. The reversal of 221608 is 806122.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 195364 + 26244 = 442^2 + 162^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×221608² = 98220211328, which contains 22 as substring.

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 plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (221603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13843 + ... + 13858.

2²²¹⁶⁰⁸ is an apocalyptic number.

It is an amenable number.

221608 is a deficient number, since it is larger than the sum of its proper divisors (193922).

221608 is a wasteful number, since it uses less digits than its factorization.

221608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27707 (or 27703 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 221608 is about 470.7525889467. The cubic root of 221608 is about 60.5148291405.

The spelling of 221608 in words is "two hundred twenty-one thousand, six hundred eight".