865876606640 has 80 divisors (see below), whose sum is σ = 2080272020736. Its totient is φ = 335177118720.

The previous prime is 865876606633. The next prime is 865876606643. The reversal of 865876606640 is 46606678568.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (62).

It is not an unprimeable number, because it can be changed into a prime (865876606643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2201624 + ... + 2564936.

Almost surely, 2^865876606640 is an apocalyptic number.

865876606640 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 865876606640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1040136010368).

865876606640 is an abundant number, since it is smaller than the sum of its proper divisors (1214395414096).

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

865876606640 is an equidigital number, since it uses as much as digits as its factorization.

865876606640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363419 (or 363351 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 62.

The spelling of 865876606640 in words is "eight hundred sixty-five billion, eight hundred seventy-six million, six hundred six thousand, six hundred forty".