20449409 has 2 divisors, whose sum is σ = 20449410. Its totient is φ = 20449408.

The previous prime is 20449399. The next prime is 20449421. The reversal of 20449409 is 90494402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14554225 + 5895184 = 3815^2 + 2428^2 .

It is a cyclic number.

It is not a de Polignac number, because 20449409 - 2⁸ = 20449153 is a prime.

It is a Chen prime.

It is equal to p_1297238 and since 20449409 and 1297238 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 (20449469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10224704 + 10224705.

It is an arithmetic number, because the mean of its divisors is an integer number (10224705).

Almost surely, 2^20449409 is an apocalyptic number.

It is an amenable number.

20449409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20449409 is an equidigital number, since it uses as much as digits as its factorization.

20449409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 20449409 is about 4522.1022765966. The cubic root of 20449409 is about 273.4598599554.

The spelling of 20449409 in words is "twenty million, four hundred forty-nine thousand, four hundred nine".