78311520 has 288 divisors, whose sum is σ = 324088128. Its totient is φ = 16809984.

The previous prime is 78311479. The next prime is 78311531. The reversal of 78311520 is 2511387.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×78311520² = 12265388329420800, which contains 22 as substring.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 171132 + ... + 171588.

It is an arithmetic number, because the mean of its divisors is an integer number (1125306).

Almost surely, 2^78311520 is an apocalyptic number.

78311520 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 78311520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162044064).

78311520 is an abundant number, since it is smaller than the sum of its proper divisors (245776608).

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

78311520 is a wasteful number, since it uses less digits than its factorization.

78311520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502 (or 491 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 78311520 is about 8849.3796392742. The cubic root of 78311520 is about 427.8339239786.

The spelling of 78311520 in words is "seventy-eight million, three hundred eleven thousand, five hundred twenty".