215715120157709 has 2 divisors, whose sum is σ = 215715120157710. Its totient is φ = 215715120157708.

The previous prime is 215715120157639. The next prime is 215715120157711. The reversal of 215715120157709 is 907751021517512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164720924953225 + 50994195204484 = 12834365^2 + 7141022^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215715120157709 is a prime.

Together with 215715120157711, 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 (215715120157769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107857560078854 + 107857560078855.

It is an arithmetic number, because the mean of its divisors is an integer number (107857560078855).

Almost surely, 2^{215715120157709} is an apocalyptic number.

It is an amenable number.

215715120157709 is a deficient number, since it is larger than the sum of its proper divisors (1).

215715120157709 is an equidigital number, since it uses as much as digits as its factorization.

215715120157709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1543500, while the sum is 53.

The spelling of 215715120157709 in words is "two hundred fifteen trillion, seven hundred fifteen billion, one hundred twenty million, one hundred fifty-seven thousand, seven hundred nine".