20400271 has 2 divisors, whose sum is σ = 20400272. Its totient is φ = 20400270.

The previous prime is 20400269. The next prime is 20400277. The reversal of 20400271 is 17200402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20400271 - 2¹ = 20400269 is a prime.

Together with 20400269, it forms a pair of twin primes.

20400271 is a modest number, since divided by 271 gives 204 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20400277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200135 + 10200136.

It is an arithmetic number, because the mean of its divisors is an integer number (10200136).

Almost surely, 2^20400271 is an apocalyptic number.

20400271 is a deficient number, since it is larger than the sum of its proper divisors (1).

20400271 is an equidigital number, since it uses as much as digits as its factorization.

20400271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 20400271 is about 4516.6659163591. The cubic root of 20400271 is about 273.2406515369.

Adding to 20400271 its reverse (17200402), we get a palindrome (37600673).

The spelling of 20400271 in words is "twenty million, four hundred thousand, two hundred seventy-one".