165408409 has 2 divisors, whose sum is σ = 165408410. Its totient is φ = 165408408.

The previous prime is 165408403. The next prime is 165408469. The reversal of 165408409 is 904804561.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 152448409 + 12960000 = 12347^2 + 3600^2 .

It is a cyclic number.

It is not a de Polignac number, because 165408409 - 2⁹ = 165407897 is a prime.

It is a super-2 number, since 2×165408409² = 54719883535822562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165408403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82704204 + 82704205.

It is an arithmetic number, because the mean of its divisors is an integer number (82704205).

Almost surely, 2^165408409 is an apocalyptic number.

It is an amenable number.

165408409 is a deficient number, since it is larger than the sum of its proper divisors (1).

165408409 is an equidigital number, since it uses as much as digits as its factorization.

165408409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 165408409 is about 12861.1200523127. The cubic root of 165408409 is about 548.9328165980.

The spelling of 165408409 in words is "one hundred sixty-five million, four hundred eight thousand, four hundred nine".