664919 has 8 divisors (see below), whose sum is σ = 696960. Its totient is φ = 633600.

The previous prime is 664891. The next prime is 664933. The reversal of 664919 is 919466.

664919 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664919 - 2⁸ = 664663 is a prime.

It is a super-2 number, since 2×664919² = 884234553122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2639 + ... + 2879.

It is an arithmetic number, because the mean of its divisors is an integer number (87120).

2⁶⁶⁴⁹¹⁹ is an apocalyptic number.

664919 is a deficient number, since it is larger than the sum of its proper divisors (32041).

664919 is a wasteful number, since it uses less digits than its factorization.

664919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361.

The product of its digits is 11664, while the sum is 35.

The square root of 664919 is about 815.4256557161. The cubic root of 664919 is about 87.2816432981.

The spelling of 664919 in words is "six hundred sixty-four thousand, nine hundred nineteen".