78771816 has 48 divisors (see below), whose sum is σ = 219113700. Its totient is φ = 25546752.

The previous prime is 78771787. The next prime is 78771817. The reversal of 78771816 is 61817787.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 74132100 + 4639716 = 8610^2 + 2154^2 .

It is not an unprimeable number, because it can be changed into a prime (78771817) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12121 + ... + 17448.

Almost surely, 2^78771816 is an apocalyptic number.

It is an amenable number.

78771816 is an abundant number, since it is smaller than the sum of its proper divisors (140341884).

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

78771816 is a wasteful number, since it uses less digits than its factorization.

78771816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29618 (or 29611 counting only the distinct ones).

The product of its digits is 131712, while the sum is 45.

The square root of 78771816 is about 8875.3487818789. The cubic root of 78771816 is about 428.6705214672.

The spelling of 78771816 in words is "seventy-eight million, seven hundred seventy-one thousand, eight hundred sixteen".