20646013 has 2 divisors, whose sum is σ = 20646014. Its totient is φ = 20646012.

The previous prime is 20646011. The next prime is 20646029. The reversal of 20646013 is 31064602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12131289 + 8514724 = 3483^2 + 2918^2 .

It is a cyclic number.

It is not a de Polignac number, because 20646013 - 2¹ = 20646011 is a prime.

Together with 20646011, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20646011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10323006 + 10323007.

It is an arithmetic number, because the mean of its divisors is an integer number (10323007).

Almost surely, 2^20646013 is an apocalyptic number.

It is an amenable number.

20646013 is a deficient number, since it is larger than the sum of its proper divisors (1).

20646013 is an equidigital number, since it uses as much as digits as its factorization.

20646013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 20646013 is about 4543.7883973618. The cubic root of 20646013 is about 274.3334291344. Note that the first 3 decimals are identical.

The spelling of 20646013 in words is "twenty million, six hundred forty-six thousand, thirteen".