20311471 has 2 divisors, whose sum is σ = 20311472. Its totient is φ = 20311470.

The previous prime is 20311469. The next prime is 20311547. The reversal of 20311471 is 17411302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20311471 - 2¹ = 20311469 is a prime.

It is a super-3 number, since 3×20311471³ (a number of 23 digits) contains 333 as substring.

Together with 20311469, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20311771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10155735 + 10155736.

It is an arithmetic number, because the mean of its divisors is an integer number (10155736).

Almost surely, 2^20311471 is an apocalyptic number.

20311471 is a deficient number, since it is larger than the sum of its proper divisors (1).

20311471 is an equidigital number, since it uses as much as digits as its factorization.

20311471 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 19.

The square root of 20311471 is about 4506.8249355838. The cubic root of 20311471 is about 272.8436133304.

Adding to 20311471 its reverse (17411302), we get a palindrome (37722773).

The spelling of 20311471 in words is "twenty million, three hundred eleven thousand, four hundred seventy-one".