51655565550 has 96 divisors (see below), whose sum is σ = 130368798720. Its totient is φ = 13532054400.

The previous prime is 51655565531. The next prime is 51655565569. The reversal of 51655565550 is 5556555615.

It is an interprime number because it is at equal distance from previous prime (51655565531) and next prime (51655565569).

It is a self number, because there is not a number n which added to its sum of digits gives 51655565550.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 8405779 + ... + 8411921.

It is an arithmetic number, because the mean of its divisors is an integer number (1358008320).

Almost surely, 2^51655565550 is an apocalyptic number.

51655565550 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 51655565550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65184399360).

51655565550 is an abundant number, since it is smaller than the sum of its proper divisors (78713233170).

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

51655565550 is a wasteful number, since it uses less digits than its factorization.

51655565550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7138 (or 7133 counting only the distinct ones).

The product of its (nonzero) digits is 2812500, while the sum is 48.

The spelling of 51655565550 in words is "fifty-one billion, six hundred fifty-five million, five hundred sixty-five thousand, five hundred fifty".