51220520 has 48 divisors (see below), whose sum is σ = 124809660. Its totient is φ = 18909696.

The previous prime is 51220501. The next prime is 51220537. The reversal of 51220520 is 2502215.

It can be written as a sum of positive squares in 6 ways, for example, as 40804 + 51179716 = 202^2 + 7154^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2972 + ... + 10548.

Almost surely, 2^51220520 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 51220520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62404830).

51220520 is an abundant number, since it is smaller than the sum of its proper divisors (73589140).

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

51220520 is a wasteful number, since it uses less digits than its factorization.

51220520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7614 (or 7597 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 51220520 is about 7156.8512629508. The cubic root of 51220520 is about 371.3767070440.

Adding to 51220520 its reverse (2502215), we get a palindrome (53722735).

The spelling of 51220520 in words is "fifty-one million, two hundred twenty thousand, five hundred twenty".