78491520 has 96 divisors (see below), whose sum is σ = 271060920. Its totient is φ = 20929536.

The previous prime is 78491471. The next prime is 78491573. The reversal of 78491520 is 2519487.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1054 + ... + 12573.

Almost surely, 2^78491520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78491520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135530460).

78491520 is an abundant number, since it is smaller than the sum of its proper divisors (192569400).

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

78491520 is a wasteful number, since it uses less digits than its factorization.

78491520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13652 (or 13637 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 78491520 is about 8859.5440063245. The cubic root of 78491520 is about 428.1614670129.

The spelling of 78491520 in words is "seventy-eight million, four hundred ninety-one thousand, five hundred twenty".