20643683 has 2 divisors, whose sum is σ = 20643684. Its totient is φ = 20643682.

The previous prime is 20643643. The next prime is 20643697. The reversal of 20643683 is 38634602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20643683 - 2¹⁰ = 20642659 is a prime.

It is equal to p_1308794 and since 20643683 and 1308794 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20643643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10321841 + 10321842.

It is an arithmetic number, because the mean of its divisors is an integer number (10321842).

Almost surely, 2^20643683 is an apocalyptic number.

20643683 is a deficient number, since it is larger than the sum of its proper divisors (1).

20643683 is an equidigital number, since it uses as much as digits as its factorization.

20643683 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 20643683 is about 4543.5319961457. The cubic root of 20643683 is about 274.3231088055.

The spelling of 20643683 in words is "twenty million, six hundred forty-three thousand, six hundred eighty-three".