161213127689 has 2 divisors, whose sum is σ = 161213127690. Its totient is φ = 161213127688.

The previous prime is 161213127611. The next prime is 161213127739. The reversal of 161213127689 is 986721312161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 142493415289 + 18719712400 = 377483^2 + 136820^2 .

It is a cyclic number.

It is not a de Polignac number, because 161213127689 - 2⁸ = 161213127433 is a prime.

It is not a weakly prime, because it can be changed into another prime (161213127389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80606563844 + 80606563845.

It is an arithmetic number, because the mean of its divisors is an integer number (80606563845).

Almost surely, 2^161213127689 is an apocalyptic number.

It is an amenable number.

161213127689 is a deficient number, since it is larger than the sum of its proper divisors (1).

161213127689 is an equidigital number, since it uses as much as digits as its factorization.

161213127689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 47.

The spelling of 161213127689 in words is "one hundred sixty-one billion, two hundred thirteen million, one hundred twenty-seven thousand, six hundred eighty-nine".