78915789 has 10 divisors (see below), whose sum is σ = 117886670. Its totient is φ = 52610472.

The previous prime is 78915787. The next prime is 78915803. The reversal of 78915789 is 98751987.

It can be written as a sum of positive squares in only one way, i.e., 78907689 + 8100 = 8883^2 + 90^2 .

It is not a de Polignac number, because 78915789 - 2¹ = 78915787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78915787) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 487054 + ... + 487215.

It is an arithmetic number, because the mean of its divisors is an integer number (11788667).

Almost surely, 2^78915789 is an apocalyptic number.

It is an amenable number.

78915789 is a deficient number, since it is larger than the sum of its proper divisors (38970881).

78915789 is an equidigital number, since it uses as much as digits as its factorization.

78915789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974281 (or 974272 counting only the distinct ones).

The product of its digits is 1270080, while the sum is 54.

The square root of 78915789 is about 8883.4559153519. The cubic root of 78915789 is about 428.9315260657.

The spelling of 78915789 in words is "seventy-eight million, nine hundred fifteen thousand, seven hundred eighty-nine".