661344 has 36 divisors (see below), whose sum is σ = 1757196. Its totient is φ = 217792.

The previous prime is 661343. The next prime is 661361. The reversal of 661344 is 443166.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661343) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7927 + ... + 8009.

It is an arithmetic number, because the mean of its divisors is an integer number (48811).

2⁶⁶¹³⁴⁴ 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 661344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (878598).

661344 is an abundant number, since it is smaller than the sum of its proper divisors (1095852).

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

661344 is an equidigital number, since it uses as much as digits as its factorization.

661344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 88 counting only the distinct ones).

The product of its digits is 1728, while the sum is 24.

The square root of 661344 is about 813.2305946040. The cubic root of 661344 is about 87.1249361031.

Multiplying 661344 by its sum of digits (24), we get a square (15872256 = 3984²).

661344 divided by its sum of digits (24) gives a square (27556 = 166²).

The spelling of 661344 in words is "six hundred sixty-one thousand, three hundred forty-four".