51717709 has 2 divisors, whose sum is σ = 51717710. Its totient is φ = 51717708.

The previous prime is 51717697. The next prime is 51717713. The reversal of 51717709 is 90771715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51696100 + 21609 = 7190^2 + 147^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51717709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51717509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25858854 + 25858855.

It is an arithmetic number, because the mean of its divisors is an integer number (25858855).

Almost surely, 2^51717709 is an apocalyptic number.

It is an amenable number.

51717709 is a deficient number, since it is larger than the sum of its proper divisors (1).

51717709 is an equidigital number, since it uses as much as digits as its factorization.

51717709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15435, while the sum is 37.

The square root of 51717709 is about 7191.5025550993. The cubic root of 51717709 is about 372.5744703443.

It can be divided in two parts, 5171 and 7709, that added together give a triangular number (12880 = T₁₆₀).

The spelling of 51717709 in words is "fifty-one million, seven hundred seventeen thousand, seven hundred nine".