20211671 has 2 divisors, whose sum is σ = 20211672. Its totient is φ = 20211670.

The previous prime is 20211661. The next prime is 20211683. The reversal of 20211671 is 17611202.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20211671 is a prime.

It is a super-2 number, since 2×20211671² = 817023289224482, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105835 + 10105836.

It is an arithmetic number, because the mean of its divisors is an integer number (10105836).

Almost surely, 2^20211671 is an apocalyptic number.

20211671 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211671 is an equidigital number, since it uses as much as digits as its factorization.

20211671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 20211671 is about 4495.7392050696. The cubic root of 20211671 is about 272.3960089131.

Adding to 20211671 its reverse (17611202), we get a palindrome (37822873).

The spelling of 20211671 in words is "twenty million, two hundred eleven thousand, six hundred seventy-one".