20001271 has 4 divisors (see below), whose sum is σ = 20691000. Its totient is φ = 19311544.

The previous prime is 20001269. The next prime is 20001277. The reversal of 20001271 is 17210002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17210002 = 2 ⋅8605001.

It is a cyclic number.

It is not a de Polignac number, because 20001271 - 2¹ = 20001269 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 (20001277) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 344821 + ... + 344878.

It is an arithmetic number, because the mean of its divisors is an integer number (5172750).

Almost surely, 2^20001271 is an apocalyptic number.

20001271 is a deficient number, since it is larger than the sum of its proper divisors (689729).

20001271 is an equidigital number, since it uses as much as digits as its factorization.

20001271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689728.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 20001271 is about 4472.2780548620. The cubic root of 20001271 is about 271.4475115790.

Adding to 20001271 its reverse (17210002), we get a palindrome (37211273).

The spelling of 20001271 in words is "twenty million, one thousand, two hundred seventy-one".