51286240729 has 4 divisors (see below), whose sum is σ = 51291650484. Its totient is φ = 51280830976.

The previous prime is 51286240723. The next prime is 51286240757. The reversal of 51286240729 is 92704268215.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25841205504 + 25445035225 = 160752^2 + 159515^2 .

It is a cyclic number.

It is not a de Polignac number, because 51286240729 - 2⁵ = 51286240697 is a prime.

It is a super-2 number, since 2×51286240729² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51286240723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2690632 + ... + 2709625.

It is an arithmetic number, because the mean of its divisors is an integer number (12822912621).

Almost surely, 2^51286240729 is an apocalyptic number.

It is an amenable number.

51286240729 is a deficient number, since it is larger than the sum of its proper divisors (5409755).

51286240729 is an equidigital number, since it uses as much as digits as its factorization.

51286240729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5409754.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 51286240729 in words is "fifty-one billion, two hundred eighty-six million, two hundred forty thousand, seven hundred twenty-nine".