51424720 has 20 divisors (see below), whose sum is σ = 119562660. Its totient is φ = 20569856.

The previous prime is 51424693. The next prime is 51424727. The reversal of 51424720 is 2742415.

It can be written as a sum of positive squares in 2 ways, for example, as 38291344 + 13133376 = 6188^2 + 3624^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51424727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 321325 + ... + 321484.

It is an arithmetic number, because the mean of its divisors is an integer number (5978133).

Almost surely, 2^51424720 is an apocalyptic number.

It is an amenable number.

51424720 is an abundant number, since it is smaller than the sum of its proper divisors (68137940).

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

51424720 is a wasteful number, since it uses less digits than its factorization.

51424720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642822 (or 642816 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 51424720 is about 7171.1031229512. The cubic root of 51424720 is about 371.8695731148.

The spelling of 51424720 in words is "fifty-one million, four hundred twenty-four thousand, seven hundred twenty".