51857440 has 48 divisors (see below), whose sum is σ = 123764760. Its totient is φ = 20531200.

The previous prime is 51857437. The next prime is 51857453. The reversal of 51857440 is 4475815.

It can be written as a sum of positive squares in 4 ways, for example, as 50865424 + 992016 = 7132^2 + 996^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51857396 and 51857405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14556 + ... + 17764.

Almost surely, 2^51857440 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 51857440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61882380).

51857440 is an abundant number, since it is smaller than the sum of its proper divisors (71907320).

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

51857440 is a wasteful number, since it uses less digits than its factorization.

51857440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3325 (or 3317 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 34.

The square root of 51857440 is about 7201.2110092678. The cubic root of 51857440 is about 372.9097094021.

The spelling of 51857440 in words is "fifty-one million, eight hundred fifty-seven thousand, four hundred forty".