51005120440 has 64 divisors (see below), whose sum is σ = 116393889600. Its totient is φ = 20112141312.

The previous prime is 51005120429. The next prime is 51005120447. The reversal of 51005120440 is 4402150015.

51005120440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×51005120440² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51005120447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8140749 + ... + 8147011.

It is an arithmetic number, because the mean of its divisors is an integer number (1818654525).

Almost surely, 2^51005120440 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 51005120440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58196944800).

51005120440 is an abundant number, since it is smaller than the sum of its proper divisors (65388769160).

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

51005120440 is a wasteful number, since it uses less digits than its factorization.

51005120440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9136 (or 9132 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

Adding to 51005120440 its reverse (4402150015), we get a palindrome (55407270455).

The spelling of 51005120440 in words is "fifty-one billion, five million, one hundred twenty thousand, four hundred forty".