78525520 has 20 divisors (see below), whose sum is σ = 182572020. Its totient is φ = 31410176.

The previous prime is 78525493. The next prime is 78525521. The reversal of 78525520 is 2552587.

It can be written as a sum of positive squares in 2 ways, for example, as 39287824 + 39237696 = 6268^2 + 6264^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78525521) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 490705 + ... + 490864.

It is an arithmetic number, because the mean of its divisors is an integer number (9128601).

Almost surely, 2^78525520 is an apocalyptic number.

It is an amenable number.

78525520 is an abundant number, since it is smaller than the sum of its proper divisors (104046500).

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

78525520 is a wasteful number, since it uses less digits than its factorization.

78525520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 981582 (or 981576 counting only the distinct ones).

The product of its (nonzero) digits is 28000, while the sum is 34.

The square root of 78525520 is about 8861.4626332226. The cubic root of 78525520 is about 428.2232800106.

The spelling of 78525520 in words is "seventy-eight million, five hundred twenty-five thousand, five hundred twenty".