51530331220 has 12 divisors (see below), whose sum is σ = 108213695604. Its totient is φ = 20612132480.

The previous prime is 51530331187. The next prime is 51530331221. The reversal of 51530331220 is 2213303515.

It can be written as a sum of positive squares in 2 ways, for example, as 15406767376 + 36123563844 = 124124^2 + 190062^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51530331221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1288258261 + ... + 1288258300.

It is an arithmetic number, because the mean of its divisors is an integer number (9017807967).

Almost surely, 2^51530331220 is an apocalyptic number.

It is an amenable number.

51530331220 is an abundant number, since it is smaller than the sum of its proper divisors (56683364384).

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

51530331220 is a wasteful number, since it uses less digits than its factorization.

51530331220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2576516570 (or 2576516568 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 25.

Adding to 51530331220 its reverse (2213303515), we get a palindrome (53743634735).

The spelling of 51530331220 in words is "fifty-one billion, five hundred thirty million, three hundred thirty-one thousand, two hundred twenty".