78383520 has 144 divisors (see below), whose sum is σ = 276854760. Its totient is φ = 20170752.

The previous prime is 78383509. The next prime is 78383527. The reversal of 78383520 is 2538387.

It can be written as a sum of positive squares in 4 ways, for example, as 67174416 + 11209104 = 8196^2 + 3348^2 .

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

It is a super-2 number, since 2×78383520² = 12287952415180800, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (78383527) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40822 + ... + 42698.

Almost surely, 2^78383520 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 78383520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138427380).

78383520 is an abundant number, since it is smaller than the sum of its proper divisors (198471240).

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

78383520 is a wasteful number, since it uses less digits than its factorization.

78383520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1927 (or 1916 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 78383520 is about 8853.4467864217. The cubic root of 78383520 is about 427.9650013598.

The spelling of 78383520 in words is "seventy-eight million, three hundred eighty-three thousand, five hundred twenty".