51565420 has 48 divisors (see below), whose sum is σ = 117784800. Its totient is φ = 18883584.

The previous prime is 51565391. The next prime is 51565427. The reversal of 51565420 is 2456515.

51565420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (51565427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10531 + ... + 14629.

It is an arithmetic number, because the mean of its divisors is an integer number (2453850).

Almost surely, 2^51565420 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 51565420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58892400).

51565420 is an abundant number, since it is smaller than the sum of its proper divisors (66219380).

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

51565420 is a wasteful number, since it uses less digits than its factorization.

51565420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4162 (or 4160 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 51565420 is about 7180.9066279962. The cubic root of 51565420 is about 372.2084140650.

The spelling of 51565420 in words is "fifty-one million, five hundred sixty-five thousand, four hundred twenty".