249475309 has 2 divisors, whose sum is σ = 249475310. Its totient is φ = 249475308.

The previous prime is 249475267. The next prime is 249475361. The reversal of 249475309 is 903574942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220077225 + 29398084 = 14835^2 + 5422^2 .

It is a cyclic number.

It is not a de Polignac number, because 249475309 - 2²⁵ = 215920877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249473309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124737654 + 124737655.

It is an arithmetic number, because the mean of its divisors is an integer number (124737655).

Almost surely, 2^249475309 is an apocalyptic number.

It is an amenable number.

249475309 is a deficient number, since it is larger than the sum of its proper divisors (1).

249475309 is an equidigital number, since it uses as much as digits as its factorization.

249475309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 249475309 is about 15794.7873996455. The cubic root of 249475309 is about 629.5195034463.

The spelling of 249475309 in words is "two hundred forty-nine million, four hundred seventy-five thousand, three hundred nine".