249221 has 4 divisors (see below), whose sum is σ = 284832. Its totient is φ = 213612.

The previous prime is 249217. The next prime is 249229. The reversal of 249221 is 122942.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122942 = 2 ⋅61471.

It is not a de Polignac number, because 249221 - 2² = 249217 is a prime.

It is a super-2 number, since 2×249221² = 124222213682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 249193 and 249202.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 249221.

It is not an unprimeable number, because it can be changed into a prime (249229) 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, 17795 + ... + 17808.

It is an arithmetic number, because the mean of its divisors is an integer number (71208).

2²⁴⁹²²¹ is an apocalyptic number.

It is an amenable number.

249221 is a deficient number, since it is larger than the sum of its proper divisors (35611).

249221 is an equidigital number, since it uses as much as digits as its factorization.

249221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35610.

The product of its digits is 288, while the sum is 20.

The square root of 249221 is about 499.2203922117. The cubic root of 249221 is about 62.9305525151.

The spelling of 249221 in words is "two hundred forty-nine thousand, two hundred twenty-one".