51917531 has 2 divisors, whose sum is σ = 51917532. Its totient is φ = 51917530.

The previous prime is 51917513. The next prime is 51917533. The reversal of 51917531 is 13571915.

It is a happy number.

51917531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (51917513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51917531 is a prime.

It is a super-2 number, since 2×51917531² = 5390860050271922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 51917533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51917533) 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, 25958765 + 25958766.

It is an arithmetic number, because the mean of its divisors is an integer number (25958766).

Almost surely, 2^51917531 is an apocalyptic number.

51917531 is a deficient number, since it is larger than the sum of its proper divisors (1).

51917531 is an equidigital number, since it uses as much as digits as its factorization.

51917531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4725, while the sum is 32.

The square root of 51917531 is about 7205.3820856357. The cubic root of 51917531 is about 373.0536930327.

The spelling of 51917531 in words is "fifty-one million, nine hundred seventeen thousand, five hundred thirty-one".