165508403 has 2 divisors, whose sum is σ = 165508404. Its totient is φ = 165508402.

The previous prime is 165508361. The next prime is 165508417. The reversal of 165508403 is 304805561.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 165508403 - 2¹⁸ = 165246259 is a prime.

It is a super-2 number, since 2×165508403² = 54786062927220818, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 165508403.

It is not a weakly prime, because it can be changed into another prime (165508703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82754201 + 82754202.

It is an arithmetic number, because the mean of its divisors is an integer number (82754202).

Almost surely, 2^165508403 is an apocalyptic number.

165508403 is a deficient number, since it is larger than the sum of its proper divisors (1).

165508403 is an equidigital number, since it uses as much as digits as its factorization.

165508403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 165508403 is about 12865.0069179927. The cubic root of 165508403 is about 549.0434093852.

The spelling of 165508403 in words is "one hundred sixty-five million, five hundred eight thousand, four hundred three".