51715440 has 240 divisors, whose sum is σ = 205510656. Its totient is φ = 11404800.

The previous prime is 51715429. The next prime is 51715451. The reversal of 51715440 is 4451715.

It is a happy number.

51715440 is a `hidden beast` number, since 51 + 71 + 544 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (51715429) and next prime (51715451).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 156075 + ... + 156405.

Almost surely, 2^51715440 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 51715440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102755328).

51715440 is an abundant number, since it is smaller than the sum of its proper divisors (153795216).

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

51715440 is a wasteful number, since it uses less digits than its factorization.

51715440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388 (or 379 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 51715440 is about 7191.3447977412. The cubic root of 51715440 is about 372.5690216379.

The spelling of 51715440 in words is "fifty-one million, seven hundred fifteen thousand, four hundred forty".