51516691200 has 1728 divisors, whose sum is σ = 229935283200. Its totient is φ = 11147673600.

The previous prime is 51516691159. The next prime is 51516691201. The reversal of 51516691200 is 219661515.

51516691200 is a `hidden beast` number, since 51 + 516 + 6 + 91 + 2 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

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

It is not an unprimeable number, because it can be changed into a prime (51516691201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 725587165 + ... + 725587235.

It is an arithmetic number, because the mean of its divisors is an integer number (133064400).

Almost surely, 2^51516691200 is an apocalyptic number.

51516691200 is a gapful number since it is divisible by the number (50) 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 51516691200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114967641600).

51516691200 is an abundant number, since it is smaller than the sum of its proper divisors (178418592000).

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

51516691200 is a wasteful number, since it uses less digits than its factorization.

51516691200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The spelling of 51516691200 in words is "fifty-one billion, five hundred sixteen million, six hundred ninety-one thousand, two hundred".