51811594240 has 104 divisors (see below), whose sum is σ = 142094846880. Its totient is φ = 17763926016.

The previous prime is 51811594223. The next prime is 51811594267. The reversal of 51811594240 is 4249511815.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 51811594193 and 51811594202.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37345 + ... + 324064.

Almost surely, 2^51811594240 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 51811594240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71047423440).

51811594240 is an abundant number, since it is smaller than the sum of its proper divisors (90283252640).

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

51811594240 is an equidigital number, since it uses as much as digits as its factorization.

51811594240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361445 (or 361423 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 40.

The spelling of 51811594240 in words is "fifty-one billion, eight hundred eleven million, five hundred ninety-four thousand, two hundred forty".