20435021 has 2 divisors, whose sum is σ = 20435022. Its totient is φ = 20435020.

The previous prime is 20434991. The next prime is 20435039. The reversal of 20435021 is 12053402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11464996 + 8970025 = 3386^2 + 2995^2 .

It is a cyclic number.

It is not a de Polignac number, because 20435021 - 2⁶ = 20434957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20432021) 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, 10217510 + 10217511.

It is an arithmetic number, because the mean of its divisors is an integer number (10217511).

Almost surely, 2^20435021 is an apocalyptic number.

It is an amenable number.

20435021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20435021 is an equidigital number, since it uses as much as digits as its factorization.

20435021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20435021 is about 4520.5111436651. The cubic root of 20435021 is about 273.3957103657.

Adding to 20435021 its reverse (12053402), we get a palindrome (32488423).

The spelling of 20435021 in words is "twenty million, four hundred thirty-five thousand, twenty-one".