664464 has 40 divisors (see below), whose sum is σ = 1745920. Its totient is φ = 217728.

The previous prime is 664459. The next prime is 664471. The reversal of 664464 is 464466.

664464 = T₃₂ + T₃₃ + ... + T₁₅₈.

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

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664464.

It is an unprimeable number.

664464 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, 5169 + ... + 5295.

It is an arithmetic number, because the mean of its divisors is an integer number (43648).

2⁶⁶⁴⁴⁶⁴ 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 664464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (872960).

664464 is an abundant number, since it is smaller than the sum of its proper divisors (1081456).

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

664464 is a wasteful number, since it uses less digits than its factorization.

664464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247 (or 241 counting only the distinct ones).

The product of its digits is 13824, while the sum is 30.

The square root of 664464 is about 815.1466125796. The cubic root of 664464 is about 87.2617299905.

It can be divided in two parts, 664 and 464, that added together give a triangular number (1128 = T₄₇).

The spelling of 664464 in words is "six hundred sixty-four thousand, four hundred sixty-four".