78115520 has 112 divisors (see below), whose sum is σ = 217797888. Its totient is φ = 26127360.

The previous prime is 78115511. The next prime is 78115523. The reversal of 78115520 is 2551187.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×78115520² = 12204068929740800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78115523) 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 15 ways as a sum of consecutive naturals, for example, 95915 + ... + 96725.

It is an arithmetic number, because the mean of its divisors is an integer number (1944624).

Almost surely, 2^78115520 is an apocalyptic number.

78115520 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78115520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108898944).

78115520 is an abundant number, since it is smaller than the sum of its proper divisors (139682368).

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

78115520 is a wasteful number, since it uses less digits than its factorization.

78115520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878 (or 868 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 29.

The square root of 78115520 is about 8838.2984787797. The cubic root of 78115520 is about 427.4766946930.

It can be divided in two parts, 7811 and 5520, that added together give a palindrome (13331).

The spelling of 78115520 in words is "seventy-eight million, one hundred fifteen thousand, five hundred twenty".