51717840 has 80 divisors (see below), whose sum is σ = 161828928. Its totient is φ = 13662208.

The previous prime is 51717833. The next prime is 51717871. The reversal of 51717840 is 4871715.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 26167 + ... + 28073.

Almost surely, 2^51717840 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 51717840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80914464).

51717840 is an abundant number, since it is smaller than the sum of its proper divisors (110111088).

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

51717840 is a wasteful number, since it uses less digits than its factorization.

51717840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2036 (or 2030 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 33.

The square root of 51717840 is about 7191.5116630650. The cubic root of 51717840 is about 372.5747849187.

The spelling of 51717840 in words is "fifty-one million, seven hundred seventeen thousand, eight hundred forty".