16517071561 has 2 divisors, whose sum is σ = 16517071562. Its totient is φ = 16517071560.

The previous prime is 16517071547. The next prime is 16517071573.

16517071561 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8568279225 + 7948792336 = 92565^2 + 89156^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 16517071561 - 2⁹ = 16517071049 is a prime.

It is not a weakly prime, because it can be changed into another prime (16517071511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8258535780 + 8258535781.

It is an arithmetic number, because the mean of its divisors is an integer number (8258535781).

Almost surely, 2^16517071561 is an apocalyptic number.

It is an amenable number.

16517071561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16517071561 is an equidigital number, since it uses as much as digits as its factorization.

16517071561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 44100, while the sum is 40.

The spelling of 16517071561 in words is "sixteen billion, five hundred seventeen million, seventy-one thousand, five hundred sixty-one".