2561328 has 180 divisors, whose sum is σ = 9400440. Its totient is φ = 665280.

The previous prime is 2561327. The next prime is 2561341. The reversal of 2561328 is 8231652.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

2561328 is a `hidden beast` number, since 25 + 613 + 28 = 666.

It is a super-2 number, since 2×2561328² = 13120802247168, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2561323) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 232843 + ... + 232853.

2^2561328 is an apocalyptic number.

2561328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2561328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4700220).

2561328 is an abundant number, since it is smaller than the sum of its proper divisors (6839112).

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

2561328 is a wasteful number, since it uses less digits than its factorization.

2561328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53 (or 23 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 2561328 is about 1600.4149461936. The cubic root of 2561328 is about 136.8217263123.

Multiplying 2561328 by its sum of digits (27), we get a square (69155856 = 8316²).

2561328 divided by its sum of digits (27) gives a square (94864 = 308²).

The spelling of 2561328 in words is "two million, five hundred sixty-one thousand, three hundred twenty-eight".