51730721280 has 800 divisors, whose sum is σ = 214039622016. Its totient is φ = 11697094656.

The previous prime is 51730721261. The next prime is 51730721291. The reversal of 51730721280 is 8212703715.

51730721280 is a `hidden beast` number, since 51 + 7 + 307 + 21 + 280 = 666.

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

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 227888527 + ... + 227888753.

Almost surely, 2^51730721280 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 51730721280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107019811008).

51730721280 is an abundant number, since it is smaller than the sum of its proper divisors (162308900736).

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

51730721280 is a wasteful number, since it uses less digits than its factorization.

51730721280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The spelling of 51730721280 in words is "fifty-one billion, seven hundred thirty million, seven hundred twenty-one thousand, two hundred eighty".