165571541 has 2 divisors, whose sum is σ = 165571542. Its totient is φ = 165571540.

The previous prime is 165571537. The next prime is 165571561. The reversal of 165571541 is 145175561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162664516 + 2907025 = 12754^2 + 1705^2 .

It is a cyclic number.

It is not a de Polignac number, because 165571541 - 2² = 165571537 is a prime.

It is a super-2 number, since 2×165571541² = 54827870378229362, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165571501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82785770 + 82785771.

It is an arithmetic number, because the mean of its divisors is an integer number (82785771).

Almost surely, 2^165571541 is an apocalyptic number.

It is an amenable number.

165571541 is a deficient number, since it is larger than the sum of its proper divisors (1).

165571541 is an equidigital number, since it uses as much as digits as its factorization.

165571541 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 165571541 is about 12867.4605497744. The cubic root of 165571541 is about 549.1132167083.

The spelling of 165571541 in words is "one hundred sixty-five million, five hundred seventy-one thousand, five hundred forty-one".