20918071 has 2 divisors, whose sum is σ = 20918072. Its totient is φ = 20918070.

The previous prime is 20918047. The next prime is 20918083. The reversal of 20918071 is 17081902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20918071 - 2⁵ = 20918039 is a prime.

It is a super-2 number, since 2×20918071² = 875131388722082, which contains 22 as substring.

It is equal to p_1325098 and since 20918071 and 1325098 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 (20918011) 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, 10459035 + 10459036.

It is an arithmetic number, because the mean of its divisors is an integer number (10459036).

Almost surely, 2^20918071 is an apocalyptic number.

20918071 is a deficient number, since it is larger than the sum of its proper divisors (1).

20918071 is an equidigital number, since it uses as much as digits as its factorization.

20918071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 20918071 is about 4573.6277723488. The cubic root of 20918071 is about 275.5331628947.

Adding to 20918071 its reverse (17081902), we get a palindrome (37999973).

The spelling of 20918071 in words is "twenty million, nine hundred eighteen thousand, seventy-one".