51611320800 has 720 divisors, whose sum is σ = 204378606432. Its totient is φ = 12599193600.

The previous prime is 51611320777. The next prime is 51611320801. The reversal of 51611320800 is 802311615.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51611320801) 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 119 ways as a sum of consecutive naturals, for example, 165952645 + ... + 165952955.

Almost surely, 2^51611320800 is an apocalyptic number.

51611320800 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 51611320800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102189303216).

51611320800 is an abundant number, since it is smaller than the sum of its proper divisors (152767285632).

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

51611320800 is a wasteful number, since it uses less digits than its factorization.

51611320800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553 (or 531 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 51611320800 in words is "fifty-one billion, six hundred eleven million, three hundred twenty thousand, eight hundred".