221081 has 4 divisors (see below), whose sum is σ = 252672. Its totient is φ = 189492.

The previous prime is 221077. The next prime is 221083. The reversal of 221081 is 180122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221081 - 2² = 221077 is a prime.

It is a super-2 number, since 2×221081² = 97753617122, which contains 22 as substring.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (221083) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15785 + ... + 15798.

It is an arithmetic number, because the mean of its divisors is an integer number (63168).

2²²¹⁰⁸¹ is an apocalyptic number.

It is an amenable number.

221081 is a deficient number, since it is larger than the sum of its proper divisors (31591).

221081 is an equidigital number, since it uses as much as digits as its factorization.

221081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31590.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 221081 is about 470.1925137643. The cubic root of 221081 is about 60.4668215048.

The spelling of 221081 in words is "two hundred twenty-one thousand, eighty-one".