51681168 has 240 divisors, whose sum is σ = 185702400. Its totient is φ = 13029120.

The previous prime is 51681167. The next prime is 51681169. The reversal of 51681168 is 86118615.

51681168 is a `hidden beast` number, since 516 + 81 + 1 + 68 = 666.

It is an interprime number because it is at equal distance from previous prime (51681167) and next prime (51681169).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51681167) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 654153 + ... + 654231.

It is an arithmetic number, because the mean of its divisors is an integer number (773760).

Almost surely, 2^51681168 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 51681168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92851200).

51681168 is an abundant number, since it is smaller than the sum of its proper divisors (134021232).

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

51681168 is a wasteful number, since it uses less digits than its factorization.

51681168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 161 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 51681168 is about 7188.9615383587. The cubic root of 51681168 is about 372.4867025267.

It can be divided in two parts, 5168 and 1168, that added together give a palindrome (6336).

The spelling of 51681168 in words is "fifty-one million, six hundred eighty-one thousand, one hundred sixty-eight".