78091816 has 64 divisors (see below), whose sum is σ = 165888000. Its totient is φ = 34157760.

The previous prime is 78091807. The next prime is 78091817. The reversal of 78091816 is 61819087.

It is not an unprimeable number, because it can be changed into a prime (78091817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 326625 + ... + 326863.

It is an arithmetic number, because the mean of its divisors is an integer number (2592000).

Almost surely, 2^78091816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78091816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82944000).

78091816 is an abundant number, since it is smaller than the sum of its proper divisors (87796184).

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

78091816 is a wasteful number, since it uses less digits than its factorization.

78091816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 78091816 is about 8836.9573949409. The cubic root of 78091816 is about 427.4334513329.

The spelling of 78091816 in words is "seventy-eight million, ninety-one thousand, eight hundred sixteen".