78985810 has 16 divisors (see below), whose sum is σ = 142291800. Its totient is φ = 31568256.

The previous prime is 78985807. The next prime is 78985811. The reversal of 78985810 is 1858987.

It can be written as a sum of positive squares in 4 ways, for example, as 75742209 + 3243601 = 8703^2 + 1801^2 .

It is a super-2 number, since 2×78985810² = 12477516362712200, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (78985811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13636 + ... + 18544.

Almost surely, 2^78985810 is an apocalyptic number.

78985810 is a deficient number, since it is larger than the sum of its proper divisors (63305990).

78985810 is a wasteful number, since it uses less digits than its factorization.

78985810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6525.

The product of its (nonzero) digits is 161280, while the sum is 46.

The square root of 78985810 is about 8887.3961316012. The cubic root of 78985810 is about 429.0583504361.

The spelling of 78985810 in words is "seventy-eight million, nine hundred eighty-five thousand, eight hundred ten".