51081856 has 64 divisors (see below), whose sum is σ = 118874880. Its totient is φ = 21408768.

The previous prime is 51081851. The next prime is 51081911. The reversal of 51081856 is 65818015.

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

It is not an unprimeable number, because it can be changed into a prime (51081851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41506 + ... + 42718.

It is an arithmetic number, because the mean of its divisors is an integer number (1857420).

Almost surely, 2^51081856 is an apocalyptic number.

51081856 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51081856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59437440).

51081856 is an abundant number, since it is smaller than the sum of its proper divisors (67793024).

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

51081856 is a wasteful number, since it uses less digits than its factorization.

51081856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1281 (or 1269 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 34.

The square root of 51081856 is about 7147.1571970959. The cubic root of 51081856 is about 371.0412742905.

The spelling of 51081856 in words is "fifty-one million, eighty-one thousand, eight hundred fifty-six".