8243187257 has 2 divisors, whose sum is σ = 8243187258. Its totient is φ = 8243187256.

The previous prime is 8243187223. The next prime is 8243187287. The reversal of 8243187257 is 7527813428.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4386280441 + 3856906816 = 66229^2 + 62104^2 .

It is a cyclic number.

It is not a de Polignac number, because 8243187257 - 2⁶ = 8243187193 is a prime.

It is not a weakly prime, because it can be changed into another prime (8243187287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4121593628 + 4121593629.

It is an arithmetic number, because the mean of its divisors is an integer number (4121593629).

Almost surely, 2^8243187257 is an apocalyptic number.

It is an amenable number.

8243187257 is a deficient number, since it is larger than the sum of its proper divisors (1).

8243187257 is an equidigital number, since it uses as much as digits as its factorization.

8243187257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 752640, while the sum is 47.

The square root of 8243187257 is about 90791.9999614503. Note that the first 4 decimals coincide. The cubic root of 8243187257 is about 2020.0636565405.

The spelling of 8243187257 in words is "eight billion, two hundred forty-three million, one hundred eighty-seven thousand, two hundred fifty-seven".