53281440 has 144 divisors (see below), whose sum is σ = 183744288. Its totient is φ = 14059008.

The previous prime is 53281411. The next prime is 53281447. The reversal of 53281440 is 4418235.

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (53281447) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 234607 + ... + 234833.

It is an arithmetic number, because the mean of its divisors is an integer number (1276002).

Almost surely, 2^53281440 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 53281440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91872144).

53281440 is an abundant number, since it is smaller than the sum of its proper divisors (130462848).

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

53281440 is a wasteful number, since it uses less digits than its factorization.

53281440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411 (or 400 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 53281440 is about 7299.4136750838. The cubic root of 53281440 is about 376.2922881944.

Adding to 53281440 its reverse (4418235), we get a palindrome (57699675).

The spelling of 53281440 in words is "fifty-three million, two hundred eighty-one thousand, four hundred forty".