861708240 has 320 divisors, whose sum is σ = 3248363520. Its totient is φ = 209018880.

The previous prime is 861708181. The next prime is 861708269. The reversal of 861708240 is 42807168.

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 = 861708195 and 861708204.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 1137942 + ... + 1138698.

It is an arithmetic number, because the mean of its divisors is an integer number (10151136).

Almost surely, 2^861708240 is an apocalyptic number.

861708240 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 861708240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1624181760).

861708240 is an abundant number, since it is smaller than the sum of its proper divisors (2386655280).

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

861708240 is a wasteful number, since it uses less digits than its factorization.

861708240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 827 (or 815 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 861708240 is about 29354.8673987807. The cubic root of 861708240 is about 951.5977692526.

The spelling of 861708240 in words is "eight hundred sixty-one million, seven hundred eight thousand, two hundred forty".