866141640 has 384 divisors, whose sum is σ = 3619728000. Its totient is φ = 182601216.

The previous prime is 866141609. The next prime is 866141641. The reversal of 866141640 is 46141668.

866141640 is a `hidden beast` number, since 8 + 6 + 6 + 1 + 4 + 1 + 640 = 666.

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 = 866141595 and 866141604.

It is not an unprimeable number, because it can be changed into a prime (866141641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 687331 + ... + 688589.

It is an arithmetic number, because the mean of its divisors is an integer number (9426375).

Almost surely, 2^866141640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866141640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1809864000).

866141640 is an abundant number, since it is smaller than the sum of its proper divisors (2753586360).

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

866141640 is a wasteful number, since it uses less digits than its factorization.

866141640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1306 (or 1289 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 866141640 is about 29430.2844022955. The cubic root of 866141640 is about 953.2269359256.

The spelling of 866141640 in words is "eight hundred sixty-six million, one hundred forty-one thousand, six hundred forty".