20973871 has 2 divisors, whose sum is σ = 20973872. Its totient is φ = 20973870.

The previous prime is 20973863. The next prime is 20973877. The reversal of 20973871 is 17837902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20973871 - 2³ = 20973863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20973871.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20973877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10486935 + 10486936.

It is an arithmetic number, because the mean of its divisors is an integer number (10486936).

Almost surely, 2^20973871 is an apocalyptic number.

20973871 is a deficient number, since it is larger than the sum of its proper divisors (1).

20973871 is an equidigital number, since it uses as much as digits as its factorization.

20973871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 20973871 is about 4579.7238999748. The cubic root of 20973871 is about 275.7779448624. Note that the first 3 decimals are identical.

The spelling of 20973871 in words is "twenty million, nine hundred seventy-three thousand, eight hundred seventy-one".