861118720 has 144 divisors (see below), whose sum is σ = 2571907968. Its totient is φ = 268369920.

The previous prime is 861118693. The next prime is 861118733. The reversal of 861118720 is 27811168.

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 15 ways as a sum of consecutive naturals, for example, 94192 + ... + 102928.

It is an arithmetic number, because the mean of its divisors is an integer number (17860472).

Almost surely, 2^861118720 is an apocalyptic number.

861118720 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 861118720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1285953984).

861118720 is an abundant number, since it is smaller than the sum of its proper divisors (1710789248).

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

861118720 is a wasteful number, since it uses less digits than its factorization.

861118720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8776 (or 8762 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 34.

The square root of 861118720 is about 29344.8244159000. The cubic root of 861118720 is about 951.3807143886.

Adding to 861118720 its reverse (27811168), we get a palindrome (888929888).

The spelling of 861118720 in words is "eight hundred sixty-one million, one hundred eighteen thousand, seven hundred twenty".