20871311 has 2 divisors, whose sum is σ = 20871312. Its totient is φ = 20871310.

The previous prime is 20871299. The next prime is 20871341. The reversal of 20871311 is 11317802.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20871311 - 2²² = 16677007 is a prime.

It is a super-2 number, since 2×20871311² = 871223245717442, which contains 22 as substring.

It is equal to p_1322339 and since 20871311 and 1322339 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20871341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435655 + 10435656.

It is an arithmetic number, because the mean of its divisors is an integer number (10435656).

Almost surely, 2^20871311 is an apocalyptic number.

20871311 is a deficient number, since it is larger than the sum of its proper divisors (1).

20871311 is an equidigital number, since it uses as much as digits as its factorization.

20871311 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 20871311 is about 4568.5129965887. The cubic root of 20871311 is about 275.3277019031.

The spelling of 20871311 in words is "twenty million, eight hundred seventy-one thousand, three hundred eleven".