665464320 has 240 divisors, whose sum is σ = 2441696400. Its totient is φ = 166920192.

The previous prime is 665464297. The next prime is 665464333. The reversal of 665464320 is 23464566.

665464320 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 643 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×665464320² = 885685522386124800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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, 390831 + ... + 392529.

It is an arithmetic number, because the mean of its divisors is an integer number (10173735).

Almost surely, 2^665464320 is an apocalyptic number.

665464320 is a gapful number since it is divisible by the number (60) 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 665464320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1220848200).

665464320 is an abundant number, since it is smaller than the sum of its proper divisors (1776232080).

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

665464320 is a wasteful number, since it uses less digits than its factorization.

665464320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1745 (or 1726 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 665464320 is about 25796.5951241632. The cubic root of 665464320 is about 873.0549754195.

The spelling of 665464320 in words is "six hundred sixty-five million, four hundred sixty-four thousand, three hundred twenty".