20021271 has 4 divisors (see below), whose sum is σ = 26695032. Its totient is φ = 13347512.

The previous prime is 20021263. The next prime is 20021297. The reversal of 20021271 is 17212002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021271 - 2³ = 20021263 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20021271.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021251) 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, 3336876 + ... + 3336881.

It is an arithmetic number, because the mean of its divisors is an integer number (6673758).

Almost surely, 2^20021271 is an apocalyptic number.

20021271 is a deficient number, since it is larger than the sum of its proper divisors (6673761).

20021271 is an equidigital number, since it uses as much as digits as its factorization.

20021271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6673760.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 20021271 is about 4474.5134931074. The cubic root of 20021271 is about 271.5379581928.

Adding to 20021271 its reverse (17212002), we get a palindrome (37233273).

The spelling of 20021271 in words is "twenty million, twenty-one thousand, two hundred seventy-one".