78909785 has 8 divisors (see below), whose sum is σ = 95629896. Its totient is φ = 62502400.

The previous prime is 78909781. The next prime is 78909797. The reversal of 78909785 is 58790987.

It can be written as a sum of positive squares in 4 ways, for example, as 8886361 + 70023424 = 2981^2 + 8368^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78909785 - 2² = 78909781 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78909781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77624 + ... + 78633.

It is an arithmetic number, because the mean of its divisors is an integer number (11953737).

Almost surely, 2^78909785 is an apocalyptic number.

It is an amenable number.

78909785 is a deficient number, since it is larger than the sum of its proper divisors (16720111).

78909785 is a wasteful number, since it uses less digits than its factorization.

78909785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156363.

The product of its (nonzero) digits is 1270080, while the sum is 53.

The square root of 78909785 is about 8883.1179773771. The cubic root of 78909785 is about 428.9206479291.

The spelling of 78909785 in words is "seventy-eight million, nine hundred nine thousand, seven hundred eighty-five".