20388871 has 2 divisors, whose sum is σ = 20388872. Its totient is φ = 20388870.

The previous prime is 20388869. The next prime is 20388883. The reversal of 20388871 is 17888302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20388871 - 2¹ = 20388869 is a prime.

Together with 20388869, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20388871.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20388811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10194435 + 10194436.

It is an arithmetic number, because the mean of its divisors is an integer number (10194436).

Almost surely, 2^20388871 is an apocalyptic number.

20388871 is a deficient number, since it is larger than the sum of its proper divisors (1).

20388871 is an equidigital number, since it uses as much as digits as its factorization.

20388871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 20388871 is about 4515.4037471748. The cubic root of 20388871 is about 273.1897449610.

The spelling of 20388871 in words is "twenty million, three hundred eighty-eight thousand, eight hundred seventy-one".