664526 has 4 divisors (see below), whose sum is σ = 996792. Its totient is φ = 332262.

The previous prime is 664511. The next prime is 664529. The reversal of 664526 is 625466.

664526 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166130 + ... + 166133.

It is an arithmetic number, because the mean of its divisors is an integer number (249198).

2⁶⁶⁴⁵²⁶ is an apocalyptic number.

664526 is a deficient number, since it is larger than the sum of its proper divisors (332266).

664526 is a wasteful number, since it uses less digits than its factorization.

664526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332265.

The product of its digits is 8640, while the sum is 29.

The square root of 664526 is about 815.1846416610. The cubic root of 664526 is about 87.2644439871.

Subtracting from 664526 its reverse (625466), we obtain a triangular number (39060 = T₂₇₉).

The spelling of 664526 in words is "six hundred sixty-four thousand, five hundred twenty-six".