51021440000 has 220 divisors, whose sum is σ = 131893327500. Its totient is φ = 19697664000.

The previous prime is 51021439999. The next prime is 51021440003. The reversal of 51021440000 is 4412015.

It can be written as a sum of positive squares in 10 ways, for example, as 46642177024 + 4379262976 = 215968^2 + 66176^2 .

It is not an unprimeable number, because it can be changed into a prime (51021440003) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18558626 + ... + 18561374.

It is an arithmetic number, because the mean of its divisors is an integer number (599515125).

Almost surely, 2^51021440000 is an apocalyptic number.

51021440000 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 51021440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65946663750).

51021440000 is an abundant number, since it is smaller than the sum of its proper divisors (80871887500).

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

51021440000 is an equidigital number, since it uses as much as digits as its factorization.

51021440000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2818 (or 2785 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

Adding to 51021440000 its reverse (4412015), we get a palindrome (51025852015).

The spelling of 51021440000 in words is "fifty-one billion, twenty-one million, four hundred forty thousand".