78164865 has 16 divisors (see below), whose sum is σ = 138960000. Its totient is φ = 41687856.

The previous prime is 78164839. The next prime is 78164887. The reversal of 78164865 is 56846187.

It is a happy number.

It is not a de Polignac number, because 78164865 - 2¹¹ = 78162817 is a prime.

It is a super-2 number, since 2×78164865² = 12219492240936450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 78164865.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 289365 + ... + 289634.

It is an arithmetic number, because the mean of its divisors is an integer number (8685000).

Almost surely, 2^78164865 is an apocalyptic number.

It is an amenable number.

78164865 is a deficient number, since it is larger than the sum of its proper divisors (60795135).

78164865 is a wasteful number, since it uses less digits than its factorization.

78164865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579013 (or 579007 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 78164865 is about 8841.0895821726. The cubic root of 78164865 is about 427.5666870421.

The spelling of 78164865 in words is "seventy-eight million, one hundred sixty-four thousand, eight hundred sixty-five".