8643650557 has 2 divisors, whose sum is σ = 8643650558. Its totient is φ = 8643650556.

The previous prime is 8643650531. The next prime is 8643650581. The reversal of 8643650557 is 7550563468.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8130809241 + 512841316 = 90171^2 + 22646^2 .

It is a cyclic number.

It is not a de Polignac number, because 8643650557 - 2¹¹ = 8643648509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8643650557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8643650597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4321825278 + 4321825279.

It is an arithmetic number, because the mean of its divisors is an integer number (4321825279).

Almost surely, 2^8643650557 is an apocalyptic number.

It is an amenable number.

8643650557 is a deficient number, since it is larger than the sum of its proper divisors (1).

8643650557 is an equidigital number, since it uses as much as digits as its factorization.

8643650557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024000, while the sum is 49.

The square root of 8643650557 is about 92971.2351052733. The cubic root of 8643650557 is about 2052.2600936832.

The spelling of 8643650557 in words is "eight billion, six hundred forty-three million, six hundred fifty thousand, five hundred fifty-seven".