51581332 has 36 divisors (see below), whose sum is σ = 105072660. Its totient is φ = 22063360.

The previous prime is 51581323. The next prime is 51581339. The reversal of 51581332 is 23318515.

It can be written as a sum of positive squares in 2 ways, for example, as 28579716 + 23001616 = 5346^2 + 4796^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 51581332.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51581339) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5094 + ... + 11362.

It is an arithmetic number, because the mean of its divisors is an integer number (2918685).

Almost surely, 2^51581332 is an apocalyptic number.

It is an amenable number.

51581332 is an abundant number, since it is smaller than the sum of its proper divisors (53491328).

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

51581332 is a wasteful number, since it uses less digits than its factorization.

51581332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6312 (or 6299 counting only the distinct ones).

The product of its digits is 3600, while the sum is 28.

The square root of 51581332 is about 7182.0144806315. The cubic root of 51581332 is about 372.2466953472.

Adding to 51581332 its reverse (23318515), we get a palindrome (74899847).

The spelling of 51581332 in words is "fifty-one million, five hundred eighty-one thousand, three hundred thirty-two".