165538403 has 2 divisors, whose sum is σ = 165538404. Its totient is φ = 165538402.

The previous prime is 165538381. The next prime is 165538423. The reversal of 165538403 is 304835561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 165538403 - 2⁶ = 165538339 is a prime.

It is a super-3 number, since 3×165538403³ (a number of 26 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (165538423) 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, 82769201 + 82769202.

It is an arithmetic number, because the mean of its divisors is an integer number (82769202).

Almost surely, 2^165538403 is an apocalyptic number.

165538403 is a deficient number, since it is larger than the sum of its proper divisors (1).

165538403 is an equidigital number, since it uses as much as digits as its factorization.

165538403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 165538403 is about 12866.1728186746. The cubic root of 165538403 is about 549.0765805252.

The spelling of 165538403 in words is "one hundred sixty-five million, five hundred thirty-eight thousand, four hundred three".