51791465640 has 128 divisors (see below), whose sum is σ = 160593592320. Its totient is φ = 13348281600.

The previous prime is 51791465633. The next prime is 51791465641. The reversal of 51791465640 is 4656419715.

It is a self number, because there is not a number n which added to its sum of digits gives 51791465640.

It is not an unprimeable number, because it can be changed into a prime (51791465641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3008337 + ... + 3025503.

It is an arithmetic number, because the mean of its divisors is an integer number (1254637440).

Almost surely, 2^51791465640 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 51791465640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80296796160).

51791465640 is an abundant number, since it is smaller than the sum of its proper divisors (108802126680).

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

51791465640 is a wasteful number, since it uses less digits than its factorization.

51791465640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18023 (or 18019 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 48.

The spelling of 51791465640 in words is "fifty-one billion, seven hundred ninety-one million, four hundred sixty-five thousand, six hundred forty".