162720809 has 4 divisors (see below), whose sum is σ = 163564116. Its totient is φ = 161877504.

The previous prime is 162720763. The next prime is 162720847. The reversal of 162720809 is 908027261.

It is a happy number.

162720809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 908027261 = 3929 ⋅231109.

It can be written as a sum of positive squares in 2 ways, for example, as 74304400 + 88416409 = 8620^2 + 9403^2 .

It is a cyclic number.

It is not a de Polignac number, because 162720809 - 2²⁰ = 161672233 is a prime.

It is a super-2 number, since 2×162720809² = 52956123363228962, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (162720109) 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, 421364 + ... + 421749.

It is an arithmetic number, because the mean of its divisors is an integer number (40891029).

Almost surely, 2^162720809 is an apocalyptic number.

It is an amenable number.

162720809 is a deficient number, since it is larger than the sum of its proper divisors (843307).

162720809 is an equidigital number, since it uses as much as digits as its factorization.

162720809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843306.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 162720809 is about 12756.2066853748. The cubic root of 162720809 is about 545.9434982478.

The spelling of 162720809 in words is "one hundred sixty-two million, seven hundred twenty thousand, eight hundred nine".