51508987 has 2 divisors, whose sum is σ = 51508988. Its totient is φ = 51508986.

The previous prime is 51508957. The next prime is 51508991. The reversal of 51508987 is 78980515.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51508987 is a prime.

It is not a weakly prime, because it can be changed into another prime (51508907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25754493 + 25754494.

It is an arithmetic number, because the mean of its divisors is an integer number (25754494).

Almost surely, 2^51508987 is an apocalyptic number.

51508987 is a deficient number, since it is larger than the sum of its proper divisors (1).

51508987 is an equidigital number, since it uses as much as digits as its factorization.

51508987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 100800, while the sum is 43.

The square root of 51508987 is about 7176.9761738493. The cubic root of 51508987 is about 372.0725833433.

The spelling of 51508987 in words is "fifty-one million, five hundred eight thousand, nine hundred eighty-seven".