165649817 has 2 divisors, whose sum is σ = 165649818. Its totient is φ = 165649816.

The previous prime is 165649787. The next prime is 165649829. The reversal of 165649817 is 718946561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165353881 + 295936 = 12859^2 + 544^2 .

It is a cyclic number.

It is not a de Polignac number, because 165649817 - 2⁶ = 165649753 is a prime.

It is not a weakly prime, because it can be changed into another prime (165649837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82824908 + 82824909.

It is an arithmetic number, because the mean of its divisors is an integer number (82824909).

Almost surely, 2^165649817 is an apocalyptic number.

It is an amenable number.

165649817 is a deficient number, since it is larger than the sum of its proper divisors (1).

165649817 is an equidigital number, since it uses as much as digits as its factorization.

165649817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 47.

The square root of 165649817 is about 12870.5018161686. The cubic root of 165649817 is about 549.1997364370.

The spelling of 165649817 in words is "one hundred sixty-five million, six hundred forty-nine thousand, eight hundred seventeen".