861786240 has 256 divisors, whose sum is σ = 3226072320. Its totient is φ = 191545344.

The previous prime is 861786229. The next prime is 861786259. The reversal of 861786240 is 42687168.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 861786192 and 861786201.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 496414 + ... + 498146.

It is an arithmetic number, because the mean of its divisors is an integer number (12601845).

Almost surely, 2^861786240 is an apocalyptic number.

861786240 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 861786240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1613036160).

861786240 is an abundant number, since it is smaller than the sum of its proper divisors (2364286080).

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

861786240 is a wasteful number, since it uses less digits than its factorization.

861786240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1799 (or 1787 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 861786240 is about 29356.1959388474. The cubic root of 861786240 is about 951.6264805894.

The spelling of 861786240 in words is "eight hundred sixty-one million, seven hundred eighty-six thousand, two hundred forty".