51330240 has 224 divisors, whose sum is σ = 195437760. Its totient is φ = 12607488.

The previous prime is 51330199. The next prime is 51330247. The reversal of 51330240 is 4203315.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (51330247) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112092 + ... + 112548.

It is an arithmetic number, because the mean of its divisors is an integer number (872490).

Almost surely, 2^51330240 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 51330240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97718880).

51330240 is an abundant number, since it is smaller than the sum of its proper divisors (144107520).

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

51330240 is a wasteful number, since it uses less digits than its factorization.

51330240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496 (or 480 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 51330240 is about 7164.5125444792. The cubic root of 51330240 is about 371.6416945379.

Adding to 51330240 its reverse (4203315), we get a palindrome (55533555).

The spelling of 51330240 in words is "fifty-one million, three hundred thirty thousand, two hundred forty".