165531481 has 2 divisors, whose sum is σ = 165531482. Its totient is φ = 165531480.

The previous prime is 165531479. The next prime is 165531517. The reversal of 165531481 is 184135561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139358025 + 26173456 = 11805^2 + 5116^2 .

It is an emirp because it is prime and its reverse (184135561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165531481 - 2¹ = 165531479 is a prime.

It is a super-2 number, since 2×165531481² = 54801342404106722, which contains 22 as substring.

Together with 165531479, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (165531281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82765740 + 82765741.

It is an arithmetic number, because the mean of its divisors is an integer number (82765741).

Almost surely, 2^165531481 is an apocalyptic number.

It is an amenable number.

165531481 is a deficient number, since it is larger than the sum of its proper divisors (1).

165531481 is an equidigital number, since it uses as much as digits as its factorization.

165531481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 34.

The square root of 165531481 is about 12865.9038159004. The cubic root of 165531481 is about 549.0689271932.

The spelling of 165531481 in words is "one hundred sixty-five million, five hundred thirty-one thousand, four hundred eighty-one".