20512161 has 12 divisors (see below), whose sum is σ = 30318288. Its totient is φ = 13356504.

The previous prime is 20512139. The next prime is 20512169. The reversal of 20512161 is 16121502.

It is not a de Polignac number, because 20512161 - 2⁹ = 20511649 is a prime.

It is a super-3 number, since 3×20512161³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20512169) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26115 + ... + 26888.

It is an arithmetic number, because the mean of its divisors is an integer number (2526524).

Almost surely, 2^20512161 is an apocalyptic number.

It is an amenable number.

20512161 is a deficient number, since it is larger than the sum of its proper divisors (9806127).

20512161 is a wasteful number, since it uses less digits than its factorization.

20512161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53052 (or 53049 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 20512161 is about 4529.0353277492. The cubic root of 20512161 is about 273.7392915058.

Adding to 20512161 its reverse (16121502), we get a palindrome (36633663).

The spelling of 20512161 in words is "twenty million, five hundred twelve thousand, one hundred sixty-one".