221097 has 4 divisors (see below), whose sum is σ = 294800. Its totient is φ = 147396.

The previous prime is 221093. The next prime is 221101. The reversal of 221097 is 790122.

It is a happy number.

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 an interprime number because it is at equal distance from previous prime (221093) and next prime (221101).

It is not a de Polignac number, because 221097 - 2² = 221093 is a prime.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (221093) 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, 36847 + ... + 36852.

It is an arithmetic number, because the mean of its divisors is an integer number (73700).

2²²¹⁰⁹⁷ is an apocalyptic number.

It is an amenable number.

221097 is a deficient number, since it is larger than the sum of its proper divisors (73703).

221097 is an equidigital number, since it uses as much as digits as its factorization.

221097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73702.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 221097 is about 470.2095277640. The cubic root of 221097 is about 60.4682801645.

The spelling of 221097 in words is "two hundred twenty-one thousand, ninety-seven".