51315320 has 64 divisors (see below), whose sum is σ = 133056000. Its totient is φ = 17447040.

The previous prime is 51315317. The next prime is 51315359. The reversal of 51315320 is 2351315.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 51315292 and 51315301.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 35981 + ... + 37379.

It is an arithmetic number, because the mean of its divisors is an integer number (2079000).

Almost surely, 2^51315320 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 51315320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66528000).

51315320 is an abundant number, since it is smaller than the sum of its proper divisors (81740680).

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

51315320 is a wasteful number, since it uses less digits than its factorization.

51315320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1548 (or 1544 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 51315320 is about 7163.4712256001. The cubic root of 51315320 is about 371.6056830730.

Adding to 51315320 its reverse (2351315), we get a palindrome (53666635).

The spelling of 51315320 in words is "fifty-one million, three hundred fifteen thousand, three hundred twenty".