20612021 has 2 divisors, whose sum is σ = 20612022. Its totient is φ = 20612020.

The previous prime is 20612003. The next prime is 20612027. The reversal of 20612021 is 12021602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20566225 + 45796 = 4535^2 + 214^2 .

It is a cyclic number.

It is not a de Polignac number, because 20612021 - 2²² = 16417717 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20611987 and 20612005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20612027) 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, 10306010 + 10306011.

It is an arithmetic number, because the mean of its divisors is an integer number (10306011).

Almost surely, 2^20612021 is an apocalyptic number.

It is an amenable number.

20612021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20612021 is an equidigital number, since it uses as much as digits as its factorization.

20612021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 20612021 is about 4540.0463654020. The cubic root of 20612021 is about 274.1827904565.

Adding to 20612021 its reverse (12021602), we get a palindrome (32633623).

The spelling of 20612021 in words is "twenty million, six hundred twelve thousand, twenty-one".