20669641 has 2 divisors, whose sum is σ = 20669642. Its totient is φ = 20669640.

The previous prime is 20669611. The next prime is 20669651. The reversal of 20669641 is 14696602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20214016 + 455625 = 4496^2 + 675^2 .

It is a cyclic number.

It is not a de Polignac number, because 20669641 - 2⁷ = 20669513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20669597 and 20669606.

It is not a weakly prime, because it can be changed into another prime (20669611) 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, 10334820 + 10334821.

It is an arithmetic number, because the mean of its divisors is an integer number (10334821).

Almost surely, 2^20669641 is an apocalyptic number.

It is an amenable number.

20669641 is a deficient number, since it is larger than the sum of its proper divisors (1).

20669641 is an equidigital number, since it uses as much as digits as its factorization.

20669641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 20669641 is about 4546.3876869444. The cubic root of 20669641 is about 274.4380414085.

It can be divided in two parts, 206 and 69641, that multiplied together give a triangular number (14346046 = T₅₃₅₆).

The spelling of 20669641 in words is "twenty million, six hundred sixty-nine thousand, six hundred forty-one".