51725440 has 64 divisors (see below), whose sum is σ = 133189560. Its totient is φ = 19095552.

The previous prime is 51725423. The next prime is 51725461. The reversal of 51725440 is 4452715.

It can be written as a sum of positive squares in 4 ways, for example, as 38241856 + 13483584 = 6184^2 + 3672^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×51725440² = 5351042286387200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51725399 and 51725408.

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, 5212 + ... + 11428.

Almost surely, 2^51725440 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 51725440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66594780).

51725440 is an abundant number, since it is smaller than the sum of its proper divisors (81464120).

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

51725440 is a wasteful number, since it uses less digits than its factorization.

51725440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6249 (or 6237 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 28.

The square root of 51725440 is about 7192.0400443824. The cubic root of 51725440 is about 372.5930341320.

The spelling of 51725440 in words is "fifty-one million, seven hundred twenty-five thousand, four hundred forty".