51978 has 8 divisors (see below), whose sum is σ = 103968. Its totient is φ = 17324.

The previous prime is 51977. The next prime is 51991. The reversal of 51978 is 87915.

51978 is nontrivially palindromic in base 11.

It is a sphenic number, since it is the product of 3 distinct primes.

51978 is an admirable number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 51978.

It is not an unprimeable number, because it can be changed into a prime (51971) 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 3 ways as a sum of consecutive naturals, for example, 4326 + ... + 4337.

It is an arithmetic number, because the mean of its divisors is an integer number (12996).

2⁵¹⁹⁷⁸ is an apocalyptic number.

51978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51984).

51978 is a wasteful number, since it uses less digits than its factorization.

51978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8668.

The product of its digits is 2520, while the sum is 30.

The square root of 51978 is about 227.9868417256. The cubic root of 51978 is about 37.3198470279.

Subtracting 51978 from its reverse (87915), we obtain a cube (35937 = 33³).

The spelling of 51978 in words is "fifty-one thousand, nine hundred seventy-eight".