8670643649 has 2 divisors, whose sum is σ = 8670643650. Its totient is φ = 8670643648.

The previous prime is 8670643643. The next prime is 8670643669. The reversal of 8670643649 is 9463460768.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8630410000 + 40233649 = 92900^2 + 6343^2 .

It is a cyclic number.

It is not a de Polignac number, because 8670643649 - 2¹² = 8670639553 is a prime.

It is a super-2 number, since 2×8670643649² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 8670643649.

It is not a weakly prime, because it can be changed into another prime (8670643643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4335321824 + 4335321825.

It is an arithmetic number, because the mean of its divisors is an integer number (4335321825).

Almost surely, 2^8670643649 is an apocalyptic number.

It is an amenable number.

8670643649 is a deficient number, since it is larger than the sum of its proper divisors (1).

8670643649 is an equidigital number, since it uses as much as digits as its factorization.

8670643649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5225472, while the sum is 53.

The square root of 8670643649 is about 93116.2909967960. The cubic root of 8670643649 is about 2054.3941950513.

The spelling of 8670643649 in words is "eight billion, six hundred seventy million, six hundred forty-three thousand, six hundred forty-nine".