20909453 has 2 divisors, whose sum is σ = 20909454. Its totient is φ = 20909452.

The previous prime is 20909431. The next prime is 20909479. The reversal of 20909453 is 35490902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18130564 + 2778889 = 4258^2 + 1667^2 .

It is a cyclic number.

It is not a de Polignac number, because 20909453 - 2⁶ = 20909389 is a prime.

It is equal to p_1324589 and since 20909453 and 1324589 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20909753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10454726 + 10454727.

It is an arithmetic number, because the mean of its divisors is an integer number (10454727).

Almost surely, 2^20909453 is an apocalyptic number.

It is an amenable number.

20909453 is a deficient number, since it is larger than the sum of its proper divisors (1).

20909453 is an equidigital number, since it uses as much as digits as its factorization.

20909453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 20909453 is about 4572.6855347815. The cubic root of 20909453 is about 275.4953188863.

The spelling of 20909453 in words is "twenty million, nine hundred nine thousand, four hundred fifty-three".