77964236809 has 4 divisors (see below), whose sum is σ = 82550368404. Its totient is φ = 73378105216.

The previous prime is 77964236797. The next prime is 77964236827. The reversal of 77964236809 is 90863246977.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 66330457209 + 11633779600 = 257547^2 + 107860^2 .

It is a cyclic number.

It is not a de Polignac number, because 77964236809 - 2¹⁹ = 77963712521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77964036809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2293065772 + ... + 2293065805.

It is an arithmetic number, because the mean of its divisors is an integer number (20637592101).

Almost surely, 2^77964236809 is an apocalyptic number.

It is an amenable number.

77964236809 is a deficient number, since it is larger than the sum of its proper divisors (4586131595).

77964236809 is a wasteful number, since it uses less digits than its factorization.

77964236809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4586131594.

The product of its (nonzero) digits is 27433728, while the sum is 61.

The spelling of 77964236809 in words is "seventy-seven billion, nine hundred sixty-four million, two hundred thirty-six thousand, eight hundred nine".