64686816547 has 2 divisors, whose sum is σ = 64686816548. Its totient is φ = 64686816546.

The previous prime is 64686816541. The next prime is 64686816589. The reversal of 64686816547 is 74561868646.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64686816547 - 2²³ = 64678427939 is a prime.

It is not a weakly prime, because it can be changed into another prime (64686816541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32343408273 + 32343408274.

It is an arithmetic number, because the mean of its divisors is an integer number (32343408274).

Almost surely, 2^64686816547 is an apocalyptic number.

64686816547 is a deficient number, since it is larger than the sum of its proper divisors (1).

64686816547 is an equidigital number, since it uses as much as digits as its factorization.

64686816547 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46448640, while the sum is 61.

The spelling of 64686816547 in words is "sixty-four billion, six hundred eighty-six million, eight hundred sixteen thousand, five hundred forty-seven".