165953923 has 4 divisors (see below), whose sum is σ = 174688360. Its totient is φ = 157219488.

The previous prime is 165953911. The next prime is 165953929. The reversal of 165953923 is 329359561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165953923 - 2⁵ = 165953891 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165953923.

It is not an unprimeable number, because it can be changed into a prime (165953929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4367190 + ... + 4367227.

It is an arithmetic number, because the mean of its divisors is an integer number (43672090).

Almost surely, 2^165953923 is an apocalyptic number.

165953923 is a deficient number, since it is larger than the sum of its proper divisors (8734437).

165953923 is an equidigital number, since it uses as much as digits as its factorization.

165953923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8734436.

The product of its digits is 218700, while the sum is 43.

The square root of 165953923 is about 12882.3104682351. The cubic root of 165953923 is about 549.5356113128.

The spelling of 165953923 in words is "one hundred sixty-five million, nine hundred fifty-three thousand, nine hundred twenty-three".