77809544947 has 2 divisors, whose sum is σ = 77809544948. Its totient is φ = 77809544946.

The previous prime is 77809544927. The next prime is 77809544983. The reversal of 77809544947 is 74944590877.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77809544947 is a prime.

It is not a weakly prime, because it can be changed into another prime (77809544927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38904772473 + 38904772474.

It is an arithmetic number, because the mean of its divisors is an integer number (38904772474).

Almost surely, 2^77809544947 is an apocalyptic number.

77809544947 is a deficient number, since it is larger than the sum of its proper divisors (1).

77809544947 is an equidigital number, since it uses as much as digits as its factorization.

77809544947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 71124480, while the sum is 64.

The spelling of 77809544947 in words is "seventy-seven billion, eight hundred nine million, five hundred forty-four thousand, nine hundred forty-seven".