78347520 has 144 divisors (see below), whose sum is σ = 278147520. Its totient is φ = 20883456.

The previous prime is 78347513. The next prime is 78347551. The reversal of 78347520 is 2574387.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×78347520² = 12276667780300800, which contains 22 as substring.

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 polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33427 + ... + 35693.

It is an arithmetic number, because the mean of its divisors is an integer number (1931580).

Almost surely, 2^78347520 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 78347520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139073760).

78347520 is an abundant number, since it is smaller than the sum of its proper divisors (199800000).

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

78347520 is a wasteful number, since it uses less digits than its factorization.

78347520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2297 (or 2277 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 78347520 is about 8851.4134464502. The cubic root of 78347520 is about 427.8994727073.

The spelling of 78347520 in words is "seventy-eight million, three hundred forty-seven thousand, five hundred twenty".