20051971 has 2 divisors, whose sum is σ = 20051972. Its totient is φ = 20051970.

The previous prime is 20051953. The next prime is 20051987. The reversal of 20051971 is 17915002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20051971 - 2¹⁵ = 20019203 is a prime.

It is not a weakly prime, because it can be changed into another prime (20051921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10025985 + 10025986.

It is an arithmetic number, because the mean of its divisors is an integer number (10025986).

Almost surely, 2^20051971 is an apocalyptic number.

20051971 is a deficient number, since it is larger than the sum of its proper divisors (1).

20051971 is an equidigital number, since it uses as much as digits as its factorization.

20051971 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 630, while the sum is 25.

The square root of 20051971 is about 4477.9427195979. The cubic root of 20051971 is about 271.6766766273.

Adding to 20051971 its reverse (17915002), we get a palindrome (37966973).

The spelling of 20051971 in words is "twenty million, fifty-one thousand, nine hundred seventy-one".