866440320 has 128 divisors (see below), whose sum is σ = 2795567040. Its totient is φ = 228225024.

The previous prime is 866440319. The next prime is 866440339. The reversal of 866440320 is 23044668.

It is a tau number, because it is divible by the number of its divisors (128).

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, 156642 + ... + 162078.

Almost surely, 2^866440320 is an apocalyptic number.

866440320 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 866440320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1397783520).

866440320 is an abundant number, since it is smaller than the sum of its proper divisors (1929126720).

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

866440320 is a wasteful number, since it uses less digits than its factorization.

866440320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5542 (or 5530 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 866440320 is about 29435.3583297367. The cubic root of 866440320 is about 953.3364934883.

Adding to 866440320 its reverse (23044668), we get a palindrome (889484988).

It can be divided in two parts, 8664 and 40320, that added together give a palindrome (48984).

The spelling of 866440320 in words is "eight hundred sixty-six million, four hundred forty thousand, three hundred twenty".