20396161 has 4 divisors (see below), whose sum is σ = 20576772. Its totient is φ = 20215552.

The previous prime is 20396153. The next prime is 20396179. The reversal of 20396161 is 16169302.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1742400 + 18653761 = 1320^2 + 4319^2 .

It is a cyclic number.

It is not a de Polignac number, because 20396161 - 2³ = 20396153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20396191) 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, 90136 + ... + 90361.

It is an arithmetic number, because the mean of its divisors is an integer number (5144193).

Almost surely, 2^20396161 is an apocalyptic number.

It is an amenable number.

20396161 is a deficient number, since it is larger than the sum of its proper divisors (180611).

20396161 is a wasteful number, since it uses less digits than its factorization.

20396161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180610.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20396161 is about 4516.2109118153. The cubic root of 20396161 is about 273.2223005633. Note that the first 3 decimals are identical.

The spelling of 20396161 in words is "twenty million, three hundred ninety-six thousand, one hundred sixty-one".