51512255240 has 16 divisors (see below), whose sum is σ = 115902574380. Its totient is φ = 20604902080.

The previous prime is 51512255239. The next prime is 51512255269. The reversal of 51512255240 is 4255221515.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 49336405924 + 2175849316 = 222118^2 + 46646^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51512255197 and 51512255206.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 643903151 + ... + 643903230.

Almost surely, 2^51512255240 is an apocalyptic number.

It is an amenable number.

51512255240 is an abundant number, since it is smaller than the sum of its proper divisors (64390319140).

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

51512255240 is a wasteful number, since it uses less digits than its factorization.

51512255240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1287806392 (or 1287806388 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 32.

Adding to 51512255240 its reverse (4255221515), we get a palindrome (55767476755).

The spelling of 51512255240 in words is "fifty-one billion, five hundred twelve million, two hundred fifty-five thousand, two hundred forty".