51581280 has 96 divisors (see below), whose sum is σ = 166507488. Its totient is φ = 13414400.

The previous prime is 51581279. The next prime is 51581297. The reversal of 51581280 is 8218515.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18370 + ... + 20990.

It is an arithmetic number, because the mean of its divisors is an integer number (1734453).

Almost surely, 2^51581280 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 51581280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83253744).

51581280 is an abundant number, since it is smaller than the sum of its proper divisors (114926208).

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

51581280 is a wasteful number, since it uses less digits than its factorization.

51581280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2680 (or 2672 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 30.

The square root of 51581280 is about 7182.0108604763. The cubic root of 51581280 is about 372.2465702578.

Adding to 51581280 its reverse (8218515), we get a palindrome (59799795).

The spelling of 51581280 in words is "fifty-one million, five hundred eighty-one thousand, two hundred eighty".