78815766 has 16 divisors (see below), whose sum is σ = 157719744. Its totient is φ = 26257224.

The previous prime is 78815761. The next prime is 78815771. The reversal of 78815766 is 66751887.

It is an interprime number because it is at equal distance from previous prime (78815761) and next prime (78815771).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78815761) 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, 16261 + ... + 20543.

It is an arithmetic number, because the mean of its divisors is an integer number (9857484).

Almost surely, 2^78815766 is an apocalyptic number.

78815766 is an abundant number, since it is smaller than the sum of its proper divisors (78903978).

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

78815766 is a wasteful number, since it uses less digits than its factorization.

78815766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7355.

The product of its digits is 564480, while the sum is 48.

The square root of 78815766 is about 8877.8243956501. The cubic root of 78815766 is about 428.7502308844.

The spelling of 78815766 in words is "seventy-eight million, eight hundred fifteen thousand, seven hundred sixty-six".