51647551 has 2 divisors, whose sum is σ = 51647552. Its totient is φ = 51647550.

The previous prime is 51647549. The next prime is 51647569. The reversal of 51647551 is 15574615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51647551 - 2¹ = 51647549 is a prime.

Together with 51647549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51647051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25823775 + 25823776.

It is an arithmetic number, because the mean of its divisors is an integer number (25823776).

Almost surely, 2^51647551 is an apocalyptic number.

51647551 is a deficient number, since it is larger than the sum of its proper divisors (1).

51647551 is an equidigital number, since it uses as much as digits as its factorization.

51647551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21000, while the sum is 34.

The square root of 51647551 is about 7186.6230595461. The cubic root of 51647551 is about 372.4059213190.

The spelling of 51647551 in words is "fifty-one million, six hundred forty-seven thousand, five hundred fifty-one".