51647780 has 24 divisors (see below), whose sum is σ = 109424952. Its totient is φ = 20475392.

The previous prime is 51647779. The next prime is 51647789. The reversal of 51647780 is 8774615.

It can be written as a sum of positive squares in 4 ways, for example, as 1747684 + 49900096 = 1322^2 + 7064^2 .

It is not an unprimeable number, because it can be changed into a prime (51647789) 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, 9167 + ... + 13686.

It is an arithmetic number, because the mean of its divisors is an integer number (4559373).

Almost surely, 2^51647780 is an apocalyptic number.

It is an amenable number.

51647780 is an abundant number, since it is smaller than the sum of its proper divisors (57777172).

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

51647780 is a wasteful number, since it uses less digits than its factorization.

51647780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22975 (or 22973 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 38.

The square root of 51647780 is about 7186.6389919071. The cubic root of 51647780 is about 372.4064717216.

The spelling of 51647780 in words is "fifty-one million, six hundred forty-seven thousand, seven hundred eighty".