20571161 has 8 divisors (see below), whose sum is σ = 22189440. Its totient is φ = 18958032.

The previous prime is 20571143. The next prime is 20571163. The reversal of 20571161 is 16117502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20571161 - 2¹⁴ = 20554777 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20571163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12746 + ... + 14268.

It is an arithmetic number, because the mean of its divisors is an integer number (2773680).

Almost surely, 2^20571161 is an apocalyptic number.

It is an amenable number.

20571161 is a deficient number, since it is larger than the sum of its proper divisors (1618279).

20571161 is a wasteful number, since it uses less digits than its factorization.

20571161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2575.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 20571161 is about 4535.5441790374. The cubic root of 20571161 is about 274.0014962534.

Adding to 20571161 its reverse (16117502), we get a palindrome (36688663).

The spelling of 20571161 in words is "twenty million, five hundred seventy-one thousand, one hundred sixty-one".