249989819 has 2 divisors, whose sum is σ = 249989820. Its totient is φ = 249989818.

The previous prime is 249989767. The next prime is 249989827. The reversal of 249989819 is 918989942.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249989819 is a prime.

It is a super-2 number, since 2×249989819² = 124989819207305522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (249989849) 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 as a sum of consecutive naturals, namely, 124994909 + 124994910.

It is an arithmetic number, because the mean of its divisors is an integer number (124994910).

Almost surely, 2^249989819 is an apocalyptic number.

249989819 is a deficient number, since it is larger than the sum of its proper divisors (1).

249989819 is an equidigital number, since it uses as much as digits as its factorization.

249989819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3359232, while the sum is 59.

The square root of 249989819 is about 15811.0663460755. The cubic root of 249989819 is about 629.9519733272.

The spelling of 249989819 in words is "two hundred forty-nine million, nine hundred eighty-nine thousand, eight hundred nineteen".