51247709 has 2 divisors, whose sum is σ = 51247710. Its totient is φ = 51247708.

The previous prime is 51247699. The next prime is 51247711. The reversal of 51247709 is 90774215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51079609 + 168100 = 7147^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 51247709 - 2²⁴ = 34470493 is a prime.

Together with 51247711, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51247759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25623854 + 25623855.

It is an arithmetic number, because the mean of its divisors is an integer number (25623855).

Almost surely, 2^51247709 is an apocalyptic number.

It is an amenable number.

51247709 is a deficient number, since it is larger than the sum of its proper divisors (1).

51247709 is an equidigital number, since it uses as much as digits as its factorization.

51247709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 51247709 is about 7158.7505194692. The cubic root of 51247709 is about 371.4424071135.

The spelling of 51247709 in words is "fifty-one million, two hundred forty-seven thousand, seven hundred nine".