861815040 has 288 divisors, whose sum is σ = 2913926400. Its totient is φ = 216760320.

The previous prime is 861814981. The next prime is 861815047. The reversal of 861815040 is 40518168.

It is a junction number, because it is equal to n+sod(n) for n = 861814992 and 861815010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861815047) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 7906506 + ... + 7906614.

It is an arithmetic number, because the mean of its divisors is an integer number (10117800).

Almost surely, 2^861815040 is an apocalyptic number.

861815040 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 861815040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1456963200).

861815040 is an abundant number, since it is smaller than the sum of its proper divisors (2052111360).

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

861815040 is a wasteful number, since it uses less digits than its factorization.

861815040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 861815040 is about 29356.6864615201. The cubic root of 861815040 is about 951.6370812604.

The spelling of 861815040 in words is "eight hundred sixty-one million, eight hundred fifteen thousand, forty".