861100640 has 96 divisors (see below), whose sum is σ = 2118057984. Its totient is φ = 330462720.

The previous prime is 861100633. The next prime is 861100679. The reversal of 861100640 is 46001168.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 629237 + ... + 630603.

It is an arithmetic number, because the mean of its divisors is an integer number (22063104).

Almost surely, 2^861100640 is an apocalyptic number.

861100640 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 861100640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1059028992).

861100640 is an abundant number, since it is smaller than the sum of its proper divisors (1256957344).

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

861100640 is a wasteful number, since it uses less digits than its factorization.

861100640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1540 (or 1532 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 861100640 is about 29344.5163531451. The cubic root of 861100640 is about 951.3740559634.

The spelling of 861100640 in words is "eight hundred sixty-one million, one hundred thousand, six hundred forty".