51509005728 has 48 divisors (see below), whose sum is σ = 136198117440. Its totient is φ = 17044338176.

The previous prime is 51509005649. The next prime is 51509005741. The reversal of 51509005728 is 82750090515.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 51509005728.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1945068 + ... + 1971371.

It is an arithmetic number, because the mean of its divisors is an integer number (2837460780).

Almost surely, 2^51509005728 is an apocalyptic number.

It is an amenable number.

51509005728 is an abundant number, since it is smaller than the sum of its proper divisors (84689111712).

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

51509005728 is a wasteful number, since it uses less digits than its factorization.

51509005728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3916589 (or 3916581 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 42.

The spelling of 51509005728 in words is "fifty-one billion, five hundred nine million, five thousand, seven hundred twenty-eight".