78243782985 has 12 divisors (see below), whose sum is σ = 135622557252. Its totient is φ = 41730017568.

The previous prime is 78243782983. The next prime is 78243782989. The reversal of 78243782985 is 58928734287.

It can be written as a sum of positive squares in 2 ways, for example, as 58160074896 + 20083708089 = 241164^2 + 141717^2 .

It is not a de Polignac number, because 78243782985 - 2¹ = 78243782983 is a prime.

It is a super-2 number, since 2×78243782985² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78243782983) 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 11 ways as a sum of consecutive naturals, for example, 869375322 + ... + 869375411.

It is an arithmetic number, because the mean of its divisors is an integer number (11301879771).

Almost surely, 2^78243782985 is an apocalyptic number.

It is an amenable number.

78243782985 is a deficient number, since it is larger than the sum of its proper divisors (57378774267).

78243782985 is a wasteful number, since it uses less digits than its factorization.

78243782985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1738750744 (or 1738750741 counting only the distinct ones).

The product of its digits is 54190080, while the sum is 63.

It can be divided in two parts, 7824 and 3782985, that added together give a square (3790809 = 1947²).

The spelling of 78243782985 in words is "seventy-eight billion, two hundred forty-three million, seven hundred eighty-two thousand, nine hundred eighty-five".