871057518167621 has 2 divisors, whose sum is σ = 871057518167622. Its totient is φ = 871057518167620.

The previous prime is 871057518167537. The next prime is 871057518167633. The reversal of 871057518167621 is 126761815750178.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639304423180900 + 231753094986721 = 25284470^2 + 15223439^2 .

It is a cyclic number.

It is not a de Polignac number, because 871057518167621 - 2³⁴ = 871040338298437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (871057518167321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 435528759083810 + 435528759083811.

It is an arithmetic number, because the mean of its divisors is an integer number (435528759083811).

Almost surely, 2^{871057518167621} is an apocalyptic number.

It is an amenable number.

871057518167621 is a deficient number, since it is larger than the sum of its proper divisors (1).

871057518167621 is an equidigital number, since it uses as much as digits as its factorization.

871057518167621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39513600, while the sum is 65.

The spelling of 871057518167621 in words is "eight hundred seventy-one trillion, fifty-seven billion, five hundred eighteen million, one hundred sixty-seven thousand, six hundred twenty-one".