165909206953 has 4 divisors (see below), whose sum is σ = 189610522240. Its totient is φ = 142207891668.

The previous prime is 165909206941. The next prime is 165909206959. The reversal of 165909206953 is 359602909561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165909206953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165909206894 and 165909206903.

It is not an unprimeable number, because it can be changed into a prime (165909206959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11850657633 + ... + 11850657646.

It is an arithmetic number, because the mean of its divisors is an integer number (47402630560).

Almost surely, 2^165909206953 is an apocalyptic number.

It is an amenable number.

165909206953 is a deficient number, since it is larger than the sum of its proper divisors (23701315287).

165909206953 is an equidigital number, since it uses as much as digits as its factorization.

165909206953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23701315286.

The product of its (nonzero) digits is 3936600, while the sum is 55.

The spelling of 165909206953 in words is "one hundred sixty-five billion, nine hundred nine million, two hundred six thousand, nine hundred fifty-three".