20671305 has 32 divisors (see below), whose sum is σ = 34214400. Its totient is φ = 10651392.

The previous prime is 20671289. The next prime is 20671307. The reversal of 20671305 is 50317602.

It is not a de Polignac number, because 20671305 - 2⁴ = 20671289 is a prime.

It is a Curzon number.

It is a zygodrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (20671307) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76711 + ... + 76979.

It is an arithmetic number, because the mean of its divisors is an integer number (1069200).

Almost surely, 2^20671305 is an apocalyptic number.

It is an amenable number.

20671305 is a deficient number, since it is larger than the sum of its proper divisors (13543095).

20671305 is a wasteful number, since it uses less digits than its factorization.

20671305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433.

The product of its (nonzero) digits is 1260, while the sum is 24.

The square root of 20671305 is about 4546.5706856927. The cubic root of 20671305 is about 274.4454057139.

Adding to 20671305 its reverse (50317602), we get a palindrome (70988907).

The spelling of 20671305 in words is "twenty million, six hundred seventy-one thousand, three hundred five".