51680 has 48 divisors (see below), whose sum is σ = 136080. Its totient is φ = 18432.

The previous prime is 51679. The next prime is 51683. The reversal of 51680 is 8615.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2711 + ... + 2729.

It is an arithmetic number, because the mean of its divisors is an integer number (2835).

2⁵¹⁶⁸⁰ 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 51680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68040).

51680 is an abundant number, since it is smaller than the sum of its proper divisors (84400).

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

51680 is a wasteful number, since it uses less digits than its factorization.

51680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 51680 is about 227.3323558141. The cubic root of 51680 is about 37.2483896426.

The spelling of 51680 in words is "fifty-one thousand, six hundred eighty".