78539825 has 96 divisors (see below), whose sum is σ = 133324800. Its totient is φ = 44478720.

The previous prime is 78539821. The next prime is 78539827. The reversal of 78539825 is 52893587.

It is not a de Polignac number, because 78539825 - 2² = 78539821 is a prime.

It is a super-2 number, since 2×78539825² = 12337008222061250, which contains 22 as substring.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 78539825.

It is not an unprimeable number, because it can be changed into a prime (78539821) 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 95 ways as a sum of consecutive naturals, for example, 994136 + ... + 994214.

It is an arithmetic number, because the mean of its divisors is an integer number (1388800).

Almost surely, 2^78539825 is an apocalyptic number.

It is an amenable number.

78539825 is a deficient number, since it is larger than the sum of its proper divisors (54784975).

78539825 is a wasteful number, since it uses less digits than its factorization.

78539825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 146 counting only the distinct ones).

The product of its digits is 604800, while the sum is 47.

The square root of 78539825 is about 8862.2697431301. The cubic root of 78539825 is about 428.2492815877.

The spelling of 78539825 in words is "seventy-eight million, five hundred thirty-nine thousand, eight hundred twenty-five".