249999989 has 4 divisors (see below), whose sum is σ = 250513824. Its totient is φ = 249486156.

The previous prime is 249999941. The next prime is 249999991. The reversal of 249999989 is 989999942.

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 a de Polignac number, because none of the positive numbers 2^k-249999989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249999089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256187 + ... + 257160.

It is an arithmetic number, because the mean of its divisors is an integer number (62628456).

Almost surely, 2^249999989 is an apocalyptic number.

It is an amenable number.

249999989 is a deficient number, since it is larger than the sum of its proper divisors (513835).

249999989 is an equidigital number, since it uses as much as digits as its factorization.

249999989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513834.

The product of its digits is 34012224, while the sum is 68.

The square root of 249999989 is about 15811.3879529914. The cubic root of 249999989 is about 629.9605157080.

The spelling of 249999989 in words is "two hundred forty-nine million, nine hundred ninety-nine thousand, nine hundred eighty-nine".