78990816 has 24 divisors (see below), whose sum is σ = 207351144. Its totient is φ = 26330240.

The previous prime is 78990811. The next prime is 78990817. The reversal of 78990816 is 61809987.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78990811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 411315 + ... + 411506.

It is an arithmetic number, because the mean of its divisors is an integer number (8639631).

Almost surely, 2^78990816 is an apocalyptic number.

It is an amenable number.

78990816 is an abundant number, since it is smaller than the sum of its proper divisors (128360328).

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

78990816 is a wasteful number, since it uses less digits than its factorization.

78990816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822834 (or 822826 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 78990816 is about 8887.6777619353. The cubic root of 78990816 is about 429.0674145990.

The spelling of 78990816 in words is "seventy-eight million, nine hundred ninety thousand, eight hundred sixteen".