51185840 has 40 divisors (see below), whose sum is σ = 119428368. Its totient is φ = 20401920.

The previous prime is 51185831. The next prime is 51185843. The reversal of 51185840 is 4858115.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 51185797 and 51185806.

It is not an unprimeable number, because it can be changed into a prime (51185843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25514 + ... + 27446.

Almost surely, 2^51185840 is an apocalyptic number.

It is an amenable number.

51185840 is an abundant number, since it is smaller than the sum of its proper divisors (68242528).

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

51185840 is a wasteful number, since it uses less digits than its factorization.

51185840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2277 (or 2271 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 32.

The square root of 51185840 is about 7154.4279994979. The cubic root of 51185840 is about 371.2928718152.

It can be divided in two parts, 51185 and 840, that added together give a palindrome (52025).

The spelling of 51185840 in words is "fifty-one million, one hundred eighty-five thousand, eight hundred forty".