866340864 has 156 divisors (see below), whose sum is σ = 2545369632. Its totient is φ = 283852800.

The previous prime is 866340857. The next prime is 866340869. The reversal of 866340864 is 468043668.

866340864 is a `hidden beast` number, since 8 + 6 + 634 + 0 + 8 + 6 + 4 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866340869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2617179 + ... + 2617509.

It is an arithmetic number, because the mean of its divisors is an integer number (16316472).

Almost surely, 2^866340864 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 866340864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1272684816).

866340864 is an abundant number, since it is smaller than the sum of its proper divisors (1679028768).

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

866340864 is a wasteful number, since it uses less digits than its factorization.

866340864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The square root of 866340864 is about 29433.6688844595. The cubic root of 866340864 is about 953.3000152450.

The spelling of 866340864 in words is "eight hundred sixty-six million, three hundred forty thousand, eight hundred sixty-four".