51721487 has 2 divisors, whose sum is σ = 51721488. Its totient is φ = 51721486.

The previous prime is 51721447. The next prime is 51721499. The reversal of 51721487 is 78412715.

51721487 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 not a de Polignac number, because 51721487 - 2⁸ = 51721231 is a prime.

It is a super-2 number, since 2×51721487² = 5350224434982338, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51721447) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25860743 + 25860744.

It is an arithmetic number, because the mean of its divisors is an integer number (25860744).

Almost surely, 2^51721487 is an apocalyptic number.

51721487 is a deficient number, since it is larger than the sum of its proper divisors (1).

51721487 is an equidigital number, since it uses as much as digits as its factorization.

51721487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15680, while the sum is 35.

The square root of 51721487 is about 7191.7652214182. The cubic root of 51721487 is about 372.5835423630.

The spelling of 51721487 in words is "fifty-one million, seven hundred twenty-one thousand, four hundred eighty-seven".