20986943 has 2 divisors, whose sum is σ = 20986944. Its totient is φ = 20986942.

The previous prime is 20986921. The next prime is 20986991. The reversal of 20986943 is 34968902.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20986943 - 2²⁰ = 19938367 is a prime.

It is a Sophie Germain prime.

It is a zygodrome in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 20986943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20986913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10493471 + 10493472.

It is an arithmetic number, because the mean of its divisors is an integer number (10493472).

Almost surely, 2^20986943 is an apocalyptic number.

20986943 is a deficient number, since it is larger than the sum of its proper divisors (1).

20986943 is an equidigital number, since it uses as much as digits as its factorization.

20986943 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 20986943 is about 4581.1508379445. The cubic root of 20986943 is about 275.8352259849.

The spelling of 20986943 in words is "twenty million, nine hundred eighty-six thousand, nine hundred forty-three".