20972071 has 2 divisors, whose sum is σ = 20972072. Its totient is φ = 20972070.

The previous prime is 20972059. The next prime is 20972087. The reversal of 20972071 is 17027902.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20972071 - 2¹⁷ = 20840999 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20972041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10486035 + 10486036.

It is an arithmetic number, because the mean of its divisors is an integer number (10486036).

Almost surely, 2^20972071 is an apocalyptic number.

20972071 is a deficient number, since it is larger than the sum of its proper divisors (1).

20972071 is an equidigital number, since it uses as much as digits as its factorization.

20972071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 20972071 is about 4579.5273773611. The cubic root of 20972071 is about 275.7700554509.

Adding to 20972071 its reverse (17027902), we get a palindrome (37999973).

The spelling of 20972071 in words is "twenty million, nine hundred seventy-two thousand, seventy-one".