78830640 has 120 divisors (see below), whose sum is σ = 302578848. Its totient is φ = 18017280.

The previous prime is 78830627. The next prime is 78830641. The reversal of 78830640 is 4603887.

78830640 is a `hidden beast` number, since 7 + 8 + 8 + 3 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a junction number, because it is equal to n+sod(n) for n = 78830595 and 78830604.

It is not an unprimeable number, because it can be changed into a prime (78830641) 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, 2781 + ... + 12860.

Almost surely, 2^78830640 is an apocalyptic number.

78830640 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 78830640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151289424).

78830640 is an abundant number, since it is smaller than the sum of its proper divisors (223748208).

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

78830640 is a wasteful number, since it uses less digits than its factorization.

78830640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15667 (or 15658 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 78830640 is about 8878.6620613694. The cubic root of 78830640 is about 428.7772002339. Note that the first 3 decimals are identical.

The spelling of 78830640 in words is "seventy-eight million, eight hundred thirty thousand, six hundred forty".