20671165 has 8 divisors (see below), whose sum is σ = 25051608. Its totient is φ = 16372800.

The previous prime is 20671163. The next prime is 20671187. The reversal of 20671165 is 56117602.

It can be written as a sum of positive squares in 4 ways, for example, as 4782969 + 15888196 = 2187^2 + 3986^2 .

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

It is not a de Polignac number, because 20671165 - 2¹ = 20671163 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20671163) 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, 19962 + ... + 20971.

It is an arithmetic number, because the mean of its divisors is an integer number (3131451).

Almost surely, 2^20671165 is an apocalyptic number.

It is an amenable number.

20671165 is a deficient number, since it is larger than the sum of its proper divisors (4380443).

20671165 is a wasteful number, since it uses less digits than its factorization.

20671165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41039.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 20671165 is about 4546.5552894472. Note that the first 3 decimals coincide. The cubic root of 20671165 is about 274.4447861362. Note that the first 3 decimals are identical.

Adding to 20671165 its reverse (56117602), we get a palindrome (76788767).

The spelling of 20671165 in words is "twenty million, six hundred seventy-one thousand, one hundred sixty-five".