51421687 has 2 divisors, whose sum is σ = 51421688. Its totient is φ = 51421686.

The previous prime is 51421649. The next prime is 51421703. The reversal of 51421687 is 78612415.

51421687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51421687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51421637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25710843 + 25710844.

It is an arithmetic number, because the mean of its divisors is an integer number (25710844).

Almost surely, 2^51421687 is an apocalyptic number.

51421687 is a deficient number, since it is larger than the sum of its proper divisors (1).

51421687 is an equidigital number, since it uses as much as digits as its factorization.

51421687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 34.

The square root of 51421687 is about 7170.8916460926. The cubic root of 51421687 is about 371.8622620875.

It can be divided in two parts, 514 and 21687, that added together give a square (22201 = 149²).

The spelling of 51421687 in words is "fifty-one million, four hundred twenty-one thousand, six hundred eighty-seven".