51561328 has 60 divisors (see below), whose sum is σ = 125174280. Its totient is φ = 20393856.

The previous prime is 51561319. The next prime is 51561329. The reversal of 51561328 is 82316515.

It is a self number, because there is not a number n which added to its sum of digits gives 51561328.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51561329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7663 + ... + 12721.

It is an arithmetic number, because the mean of its divisors is an integer number (2086238).

Almost surely, 2^51561328 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 51561328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62587140).

51561328 is an abundant number, since it is smaller than the sum of its proper divisors (73612952).

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

51561328 is a wasteful number, since it uses less digits than its factorization.

51561328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5094 (or 5081 counting only the distinct ones).

The product of its digits is 7200, while the sum is 31.

The square root of 51561328 is about 7180.6217001037. The cubic root of 51561328 is about 372.1985682088.

The spelling of 51561328 in words is "fifty-one million, five hundred sixty-one thousand, three hundred twenty-eight".