20653909 has 2 divisors, whose sum is σ = 20653910. Its totient is φ = 20653908.

The previous prime is 20653907. The next prime is 20653921. The reversal of 20653909 is 90935602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13118884 + 7535025 = 3622^2 + 2745^2 .

It is a cyclic number.

It is not a de Polignac number, because 20653909 - 2¹ = 20653907 is a prime.

Together with 20653907, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20653901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10326954 + 10326955.

It is an arithmetic number, because the mean of its divisors is an integer number (10326955).

Almost surely, 2^20653909 is an apocalyptic number.

It is an amenable number.

20653909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20653909 is an equidigital number, since it uses as much as digits as its factorization.

20653909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 34.

The square root of 20653909 is about 4544.6571927924. The cubic root of 20653909 is about 274.3683973173.

The spelling of 20653909 in words is "twenty million, six hundred fifty-three thousand, nine hundred nine".