51687439 has 2 divisors, whose sum is σ = 51687440. Its totient is φ = 51687438.

The previous prime is 51687413. The next prime is 51687469. The reversal of 51687439 is 93478615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51687439 - 2⁹ = 51686927 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51687395 and 51687404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51687469) by changing a digit.

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 as a sum of consecutive naturals, namely, 25843719 + 25843720.

It is an arithmetic number, because the mean of its divisors is an integer number (25843720).

Almost surely, 2^51687439 is an apocalyptic number.

51687439 is a deficient number, since it is larger than the sum of its proper divisors (1).

51687439 is an equidigital number, since it uses as much as digits as its factorization.

51687439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 43.

The square root of 51687439 is about 7189.3976799173. The cubic root of 51687439 is about 372.5017677798.

The spelling of 51687439 in words is "fifty-one million, six hundred eighty-seven thousand, four hundred thirty-nine".