161152206581 has 2 divisors, whose sum is σ = 161152206582. Its totient is φ = 161152206580.

The previous prime is 161152206559. The next prime is 161152206601. The reversal of 161152206581 is 185602251161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 154284769681 + 6867436900 = 392791^2 + 82870^2 .

It is a cyclic number.

It is not a de Polignac number, because 161152206581 - 2³⁰ = 160078464757 is a prime.

It is a super-2 number, since 2×161152206581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161152206521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80576103290 + 80576103291.

It is an arithmetic number, because the mean of its divisors is an integer number (80576103291).

Almost surely, 2^161152206581 is an apocalyptic number.

It is an amenable number.

161152206581 is a deficient number, since it is larger than the sum of its proper divisors (1).

161152206581 is an equidigital number, since it uses as much as digits as its factorization.

161152206581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28800, while the sum is 38.

The spelling of 161152206581 in words is "one hundred sixty-one billion, one hundred fifty-two million, two hundred six thousand, five hundred eighty-one".