249861247 has 2 divisors, whose sum is σ = 249861248. Its totient is φ = 249861246.

The previous prime is 249861217. The next prime is 249861253. The reversal of 249861247 is 742168942.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 249861247 - 2²³ = 241472639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249861217) 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, 124930623 + 124930624.

It is an arithmetic number, because the mean of its divisors is an integer number (124930624).

Almost surely, 2^249861247 is an apocalyptic number.

249861247 is a deficient number, since it is larger than the sum of its proper divisors (1).

249861247 is an equidigital number, since it uses as much as digits as its factorization.

249861247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 43.

The square root of 249861247 is about 15806.9999367369. Note that the first 4 decimals coincide. The cubic root of 249861247 is about 629.8439581625.

The spelling of 249861247 in words is "two hundred forty-nine million, eight hundred sixty-one thousand, two hundred forty-seven".