165919903 has 2 divisors, whose sum is σ = 165919904. Its totient is φ = 165919902.

The previous prime is 165919883. The next prime is 165919921. The reversal of 165919903 is 309919561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 165919903 - 2²¹ = 163822751 is a prime.

It is equal to p_9287386 and since 165919903 and 9287386 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165919903.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165919973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82959951 + 82959952.

It is an arithmetic number, because the mean of its divisors is an integer number (82959952).

Almost surely, 2^165919903 is an apocalyptic number.

165919903 is a deficient number, since it is larger than the sum of its proper divisors (1).

165919903 is an equidigital number, since it uses as much as digits as its factorization.

165919903 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 65610, while the sum is 43.

The square root of 165919903 is about 12880.9899852457. The cubic root of 165919903 is about 549.4980577582.

The spelling of 165919903 in words is "one hundred sixty-five million, nine hundred nineteen thousand, nine hundred three".