249621 has 4 divisors (see below), whose sum is σ = 332832. Its totient is φ = 166412.

The previous prime is 249607. The next prime is 249647. The reversal of 249621 is 126942.

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 249621 - 2⁵ = 249589 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 249591 and 249600.

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 249621.

It is not an unprimeable number, because it can be changed into a prime (249671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41601 + ... + 41606.

It is an arithmetic number, because the mean of its divisors is an integer number (83208).

2²⁴⁹⁶²¹ is an apocalyptic number.

It is an amenable number.

249621 is a deficient number, since it is larger than the sum of its proper divisors (83211).

249621 is an equidigital number, since it uses as much as digits as its factorization.

249621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83210.

The product of its digits is 864, while the sum is 24.

The square root of 249621 is about 499.6208562500. The cubic root of 249621 is about 62.9642023892.

The spelling of 249621 in words is "two hundred forty-nine thousand, six hundred twenty-one".