20581871 has 2 divisors, whose sum is σ = 20581872. Its totient is φ = 20581870.

The previous prime is 20581831. The next prime is 20581901. The reversal of 20581871 is 17818502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20581871 is a prime.

It is a super-2 number, since 2×20581871² = 847226827721282, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20581811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10290935 + 10290936.

It is an arithmetic number, because the mean of its divisors is an integer number (10290936).

Almost surely, 2^20581871 is an apocalyptic number.

20581871 is a deficient number, since it is larger than the sum of its proper divisors (1).

20581871 is an equidigital number, since it uses as much as digits as its factorization.

20581871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 20581871 is about 4536.7246996043. The cubic root of 20581871 is about 274.0490392984.

The spelling of 20581871 in words is "twenty million, five hundred eighty-one thousand, eight hundred seventy-one".