78485703409 has 9 divisors (see below), whose sum is σ = 80458453729. Its totient is φ = 76560211840.

The previous prime is 78485703407. The next prime is 78485703419. The reversal of 78485703409 is 90430758487.

The square root of 78485703409 is 280153.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 54730263025 + 23755440384 = 233945^2 + 154128^2 .

It is not a de Polignac number, because 78485703409 - 2¹ = 78485703407 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78485703409.

It is not an unprimeable number, because it can be changed into a prime (78485703407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 11482857 + ... + 11489689.

Almost surely, 2^78485703409 is an apocalyptic number.

78485703409 is the 280153-rd square number.

78485703409 is the 140077-th centered octagonal number.

It is an amenable number.

78485703409 is a deficient number, since it is larger than the sum of its proper divisors (1972750320).

78485703409 is an frugal number, since it uses more digits than its factorization.

78485703409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13748 (or 6874 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 55.

The spelling of 78485703409 in words is "seventy-eight billion, four hundred eighty-five million, seven hundred three thousand, four hundred nine".