51245309 has 2 divisors, whose sum is σ = 51245310. Its totient is φ = 51245308.

The previous prime is 51245273. The next prime is 51245317. The reversal of 51245309 is 90354215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46308025 + 4937284 = 6805^2 + 2222^2 .

It is a cyclic number.

It is not a de Polignac number, because 51245309 - 2⁸ = 51245053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51245339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25622654 + 25622655.

It is an arithmetic number, because the mean of its divisors is an integer number (25622655).

Almost surely, 2^51245309 is an apocalyptic number.

It is an amenable number.

51245309 is a deficient number, since it is larger than the sum of its proper divisors (1).

51245309 is an equidigital number, since it uses as much as digits as its factorization.

51245309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 51245309 is about 7158.5828904889. The cubic root of 51245309 is about 371.4366086384.

The spelling of 51245309 in words is "fifty-one million, two hundred forty-five thousand, three hundred nine".