51436240 has 20 divisors (see below), whose sum is σ = 119589444. Its totient is φ = 20574464.

The previous prime is 51436201. The next prime is 51436241. The reversal of 51436240 is 4263415.

It can be written as a sum of positive squares in 2 ways, for example, as 36288576 + 15147664 = 6024^2 + 3892^2 .

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 (51436241) 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, 321397 + ... + 321556.

Almost surely, 2^51436240 is an apocalyptic number.

It is an amenable number.

51436240 is an abundant number, since it is smaller than the sum of its proper divisors (68153204).

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

51436240 is a wasteful number, since it uses less digits than its factorization.

51436240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642966 (or 642960 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 51436240 is about 7171.9063016746. The cubic root of 51436240 is about 371.8973393825.

Adding to 51436240 its reverse (4263415), we get a palindrome (55699655).

The spelling of 51436240 in words is "fifty-one million, four hundred thirty-six thousand, two hundred forty".