161755541 has 2 divisors, whose sum is σ = 161755542. Its totient is φ = 161755540.

The previous prime is 161755511. The next prime is 161755547. The reversal of 161755541 is 145557161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151167025 + 10588516 = 12295^2 + 3254^2 .

It is an emirp because it is prime and its reverse (145557161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161755541 - 2²⁶ = 94646677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161755547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80877770 + 80877771.

It is an arithmetic number, because the mean of its divisors is an integer number (80877771).

Almost surely, 2^161755541 is an apocalyptic number.

It is an amenable number.

161755541 is a deficient number, since it is larger than the sum of its proper divisors (1).

161755541 is an equidigital number, since it uses as much as digits as its factorization.

161755541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21000, while the sum is 35.

The square root of 161755541 is about 12718.3151792995. The cubic root of 161755541 is about 544.8618351893.

The spelling of 161755541 in words is "one hundred sixty-one million, seven hundred fifty-five thousand, five hundred forty-one".