665822544 has 80 divisors (see below), whose sum is σ = 1825686720. Its totient is φ = 208373760.

The previous prime is 665822543. The next prime is 665822551. The reversal of 665822544 is 445228566.

It is a happy number.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 665822496 and 665822505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665822543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 465222 + ... + 466650.

It is an arithmetic number, because the mean of its divisors is an integer number (22821084).

Almost surely, 2^665822544 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 665822544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (912843360).

665822544 is an abundant number, since it is smaller than the sum of its proper divisors (1159864176).

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

665822544 is a wasteful number, since it uses less digits than its factorization.

665822544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2028 (or 2022 counting only the distinct ones).

The product of its digits is 460800, while the sum is 42.

The square root of 665822544 is about 25803.5374319104. The cubic root of 665822544 is about 873.2116044751.

The spelling of 665822544 in words is "six hundred sixty-five million, eight hundred twenty-two thousand, five hundred forty-four".