664416 has 48 divisors (see below), whose sum is σ = 1940400. Its totient is φ = 221184.

The previous prime is 664403. The next prime is 664421. The reversal of 664416 is 614466.

664416 is a `hidden beast` number, since 6 + 644 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 664416.

It is a congruent number.

It is an unprimeable number.

664416 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 480 + ... + 1248.

It is an arithmetic number, because the mean of its divisors is an integer number (40425).

2⁶⁶⁴⁴¹⁶ 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 664416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (970200).

664416 is an abundant number, since it is smaller than the sum of its proper divisors (1275984).

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

664416 is a wasteful number, since it uses less digits than its factorization.

664416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788 (or 774 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 664416 is about 815.1171694916. The cubic root of 664416 is about 87.2596287160.

The spelling of 664416 in words is "six hundred sixty-four thousand, four hundred sixteen".