51000551000 has 128 divisors (see below), whose sum is σ = 137146988160. Its totient is φ = 17388864000.

The previous prime is 51000550901. The next prime is 51000551009. The reversal of 51000551000 is 15500015.

It is a self number, because there is not a number n which added to its sum of digits gives 51000551000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51000551009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1246874 + ... + 1287126.

It is an arithmetic number, because the mean of its divisors is an integer number (1071460845).

Almost surely, 2^51000551000 is an apocalyptic number.

51000551000 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 51000551000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68573494080).

51000551000 is an abundant number, since it is smaller than the sum of its proper divisors (86146437160).

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

51000551000 is a wasteful number, since it uses less digits than its factorization.

51000551000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40462 (or 40448 counting only the distinct ones).

The product of its (nonzero) digits is 125, while the sum is 17.

The spelling of 51000551000 in words is "fifty-one billion, five hundred fifty-one thousand".