51243040 has 24 divisors (see below), whose sum is σ = 121062060. Its totient is φ = 20497152.

The previous prime is 51243013. The next prime is 51243041. The reversal of 51243040 is 4034215.

It can be written as a sum of positive squares in 2 ways, for example, as 44462224 + 6780816 = 6668^2 + 2604^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51242999 and 51243017.

It is not an unprimeable number, because it can be changed into a prime (51243041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159975 + ... + 160294.

Almost surely, 2^51243040 is an apocalyptic number.

It is an amenable number.

51243040 is an abundant number, since it is smaller than the sum of its proper divisors (69819020).

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

51243040 is a wasteful number, since it uses less digits than its factorization.

51243040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320284 (or 320276 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 51243040 is about 7158.4244076473. The cubic root of 51243040 is about 371.4311264969.

Adding to 51243040 its reverse (4034215), we get a palindrome (55277255).

The spelling of 51243040 in words is "fifty-one million, two hundred forty-three thousand, forty".