51780040 has 32 divisors (see below), whose sum is σ = 125468280. Its totient is φ = 19118592.

The previous prime is 51780031. The next prime is 51780101. The reversal of 51780040 is 4008715.

It can be written as a sum of positive squares in 4 ways, for example, as 41139396 + 10640644 = 6414^2 + 3262^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51779987 and 51780014.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49269 + ... + 50308.

Almost surely, 2^51780040 is an apocalyptic number.

It is an amenable number.

51780040 is an abundant number, since it is smaller than the sum of its proper divisors (73688240).

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

51780040 is a wasteful number, since it uses less digits than its factorization.

51780040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99601 (or 99597 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 51780040 is about 7195.8349063886. The cubic root of 51780040 is about 372.7240877993.

Adding to 51780040 its reverse (4008715), we get a palindrome (55788755).

The spelling of 51780040 in words is "fifty-one million, seven hundred eighty thousand, forty".