866647019520 has 312 divisors, whose sum is σ = 3115287092736. Its totient is φ = 231104544768.

The previous prime is 866647019473. The next prime is 866647019543. The reversal of 866647019520 is 25910746668.

It is a super-2 number, since 2×866647019520² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4889569 + ... + 5063711.

It is an arithmetic number, because the mean of its divisors is an integer number (9984894528).

Almost surely, 2^866647019520 is an apocalyptic number.

866647019520 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 866647019520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1557643546368).

866647019520 is an abundant number, since it is smaller than the sum of its proper divisors (2248640073216).

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

866647019520 is an equidigital number, since it uses as much as digits as its factorization.

866647019520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174187 (or 174153 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 866647019520 in words is "eight hundred sixty-six billion, six hundred forty-seven million, nineteen thousand, five hundred twenty".