249930721 has 4 divisors (see below), whose sum is σ = 253450944. Its totient is φ = 246410500.

The previous prime is 249930713. The next prime is 249930727. The reversal of 249930721 is 127039942.

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 249930721 - 2³ = 249930713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249930727) 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, 1760005 + ... + 1760146.

It is an arithmetic number, because the mean of its divisors is an integer number (63362736).

Almost surely, 2^249930721 is an apocalyptic number.

It is an amenable number.

249930721 is a deficient number, since it is larger than the sum of its proper divisors (3520223).

249930721 is an equidigital number, since it uses as much as digits as its factorization.

249930721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3520222.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 249930721 is about 15809.1973547046. The cubic root of 249930721 is about 629.9023288578.

The spelling of 249930721 in words is "two hundred forty-nine million, nine hundred thirty thousand, seven hundred twenty-one".