78764778 has 16 divisors (see below), whose sum is σ = 175032960. Its totient is φ = 26254908.

The previous prime is 78764753. The next prime is 78764789. The reversal of 78764778 is 87746787.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 1458607 = 78764778 / (7 + 8 + 7 + 6 + 4 + 7 + 7 + 8).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 729250 + ... + 729357.

It is an arithmetic number, because the mean of its divisors is an integer number (10939560).

Almost surely, 2^78764778 is an apocalyptic number.

78764778 is an abundant number, since it is smaller than the sum of its proper divisors (96268182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78764778 is a wasteful number, since it uses less digits than its factorization.

78764778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1458618 (or 1458612 counting only the distinct ones).

The product of its digits is 3687936, while the sum is 54.

The square root of 78764778 is about 8874.9522815619. The cubic root of 78764778 is about 428.6577543248.

Subtracting 78764778 from its reverse (87746787), we obtain a square (8982009 = 2997²).

The spelling of 78764778 in words is "seventy-eight million, seven hundred sixty-four thousand, seven hundred seventy-eight".