861666080 has 192 divisors, whose sum is σ = 2429844480. Its totient is φ = 285081600.

The previous prime is 861666079. The next prime is 861666107. The reversal of 861666080 is 80666168.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 927056 + ... + 927984.

It is an arithmetic number, because the mean of its divisors is an integer number (12655440).

Almost surely, 2^861666080 is an apocalyptic number.

861666080 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 861666080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1214922240).

861666080 is an abundant number, since it is smaller than the sum of its proper divisors (1568178400).

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

861666080 is a wasteful number, since it uses less digits than its factorization.

861666080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1003 (or 995 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 861666080 is about 29354.1492808087. The cubic root of 861666080 is about 951.5822496856.

The spelling of 861666080 in words is "eight hundred sixty-one million, six hundred sixty-six thousand, eighty".