51535440 has 240 divisors, whose sum is σ = 196612416. Its totient is φ = 12441600.

The previous prime is 51535411. The next prime is 51535441. The reversal of 51535440 is 4453515.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51535441) 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 47 ways as a sum of consecutive naturals, for example, 213720 + ... + 213960.

Almost surely, 2^51535440 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 51535440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98306208).

51535440 is an abundant number, since it is smaller than the sum of its proper divisors (145076976).

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

51535440 is a wasteful number, since it uses less digits than its factorization.

51535440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The square root of 51535440 is about 7178.8188443504. The cubic root of 51535440 is about 372.1362664156.

Adding to 51535440 its reverse (4453515), we get a palindrome (55988955).

The spelling of 51535440 in words is "fifty-one million, five hundred thirty-five thousand, four hundred forty".