247323509 has 2 divisors, whose sum is σ = 247323510. Its totient is φ = 247323508.

The previous prime is 247323499. The next prime is 247323529. The reversal of 247323509 is 905323742.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144240100 + 103083409 = 12010^2 + 10153^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-247323509 is a prime.

It is a super-2 number, since 2×247323509² = 122337836208146162, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247323529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123661754 + 123661755.

It is an arithmetic number, because the mean of its divisors is an integer number (123661755).

Almost surely, 2^247323509 is an apocalyptic number.

It is an amenable number.

247323509 is a deficient number, since it is larger than the sum of its proper divisors (1).

247323509 is an equidigital number, since it uses as much as digits as its factorization.

247323509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 35.

The square root of 247323509 is about 15726.5224700186. The cubic root of 247323509 is about 627.7043425859.

The spelling of 247323509 in words is "two hundred forty-seven million, three hundred twenty-three thousand, five hundred nine".