661304 has 32 divisors (see below), whose sum is σ = 1452000. Its totient is φ = 282240.

The previous prime is 661267. The next prime is 661321. The reversal of 661304 is 403166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2624 + ... + 2864.

It is an arithmetic number, because the mean of its divisors is an integer number (45375).

2⁶⁶¹³⁰⁴ 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 661304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (726000).

661304 is an abundant number, since it is smaller than the sum of its proper divisors (790696).

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

661304 is a wasteful number, since it uses less digits than its factorization.

661304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 661304 is about 813.2060009616. The cubic root of 661304 is about 87.1231795449.

The spelling of 661304 in words is "six hundred sixty-one thousand, three hundred four".