51918720 has 128 divisors (see below), whose sum is σ = 189181440. Its totient is φ = 11864064.

The previous prime is 51918719. The next prime is 51918739. The reversal of 51918720 is 2781915.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11509 + ... + 15371.

It is an arithmetic number, because the mean of its divisors is an integer number (1477980).

Almost surely, 2^51918720 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 51918720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94590720).

51918720 is an abundant number, since it is smaller than the sum of its proper divisors (137262720).

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

51918720 is a wasteful number, since it uses less digits than its factorization.

51918720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3892 (or 3880 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 51918720 is about 7205.4645929322. The cubic root of 51918720 is about 373.0565408662.

The spelling of 51918720 in words is "fifty-one million, nine hundred eighteen thousand, seven hundred twenty".