861880320 has 360 divisors, whose sum is σ = 3435030144. Its totient is φ = 195821568.

The previous prime is 861880307. The next prime is 861880363. The reversal of 861880320 is 23088168.

861880320 is a `hidden beast` number, since 8 + 618 + 8 + 0 + 32 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

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 (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5160877 + ... + 5161043.

Almost surely, 2^861880320 is an apocalyptic number.

861880320 is a gapful number since it is divisible by the number (80) 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 861880320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1717515072).

861880320 is an abundant number, since it is smaller than the sum of its proper divisors (2573149824).

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

861880320 is a wasteful number, since it uses less digits than its factorization.

861880320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 861880320 is about 29357.7982825688. The cubic root of 861880320 is about 951.6611085739.

The spelling of 861880320 in words is "eight hundred sixty-one million, eight hundred eighty thousand, three hundred twenty".