20971799 has 2 divisors, whose sum is σ = 20971800. Its totient is φ = 20971798.

The previous prime is 20971793. The next prime is 20971807. The reversal of 20971799 is 99717902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20971799 - 2²⁰ = 19923223 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 (20971793) 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, 10485899 + 10485900.

It is an arithmetic number, because the mean of its divisors is an integer number (10485900).

Almost surely, 2^20971799 is an apocalyptic number.

20971799 is a deficient number, since it is larger than the sum of its proper divisors (1).

20971799 is an equidigital number, since it uses as much as digits as its factorization.

20971799 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 71442, while the sum is 44.

The square root of 20971799 is about 4579.4976798771. The cubic root of 20971799 is about 275.7688632339.

The spelling of 20971799 in words is "twenty million, nine hundred seventy-one thousand, seven hundred ninety-nine".