78669012609 has 72 divisors (see below), whose sum is σ = 132749646120. Its totient is φ = 44703943680.

The previous prime is 78669012599. The next prime is 78669012637. The reversal of 78669012609 is 90621096687.

It can be written as a sum of positive squares in 4 ways, for example, as 11715897600 + 66953115009 = 108240^2 + 258753^2 .

It is not a de Polignac number, because 78669012609 - 2⁸ = 78669012353 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78669012679) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4972099 + ... + 4987895.

It is an arithmetic number, because the mean of its divisors is an integer number (1843745085).

Almost surely, 2^78669012609 is an apocalyptic number.

It is an amenable number.

78669012609 is a deficient number, since it is larger than the sum of its proper divisors (54080633511).

78669012609 is a wasteful number, since it uses less digits than its factorization.

78669012609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16111 (or 16097 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 78669012609 in words is "seventy-eight billion, six hundred sixty-nine million, twelve thousand, six hundred nine".