664929 has 10 divisors (see below), whose sum is σ = 993410. Its totient is φ = 443232.

The previous prime is 664891. The next prime is 664933. The reversal of 664929 is 929466.

664929 is a `hidden beast` number, since 6 + 649 + 2 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 419904 + 245025 = 648^2 + 495^2 .

It is not a de Polignac number, because 664929 - 2¹² = 660833 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 664893 and 664902.

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 9 ways as a sum of consecutive naturals, for example, 4024 + ... + 4185.

It is an arithmetic number, because the mean of its divisors is an integer number (99341).

2⁶⁶⁴⁹²⁹ is an apocalyptic number.

It is an amenable number.

664929 is a deficient number, since it is larger than the sum of its proper divisors (328481).

664929 is an equidigital number, since it uses as much as digits as its factorization.

664929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8221 (or 8212 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 664929 is about 815.4317874599. The cubic root of 664929 is about 87.2820808512.

Subtracting from 664929 its product of digits (23328), we obtain a square (641601 = 801²).

The spelling of 664929 in words is "six hundred sixty-four thousand, nine hundred twenty-nine".