51138778860 has 144 divisors (see below), whose sum is σ = 170205706944. Its totient is φ = 12350467584.

The previous prime is 51138778853. The next prime is 51138778879. The reversal of 51138778860 is 6887783115.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 51138778797 and 51138778806.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 82152 + ... + 330191.

It is an arithmetic number, because the mean of its divisors is an integer number (1181984076).

Almost surely, 2^51138778860 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 51138778860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85102853472).

51138778860 is an abundant number, since it is smaller than the sum of its proper divisors (119066928084).

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

51138778860 is a wasteful number, since it uses less digits than its factorization.

51138778860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412424 (or 412419 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 54.

The spelling of 51138778860 in words is "fifty-one billion, one hundred thirty-eight million, seven hundred seventy-eight thousand, eight hundred sixty".