20644367 has 2 divisors, whose sum is σ = 20644368. Its totient is φ = 20644366.

The previous prime is 20644333. The next prime is 20644369. The reversal of 20644367 is 76344602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20644367 - 2⁶ = 20644303 is a prime.

Together with 20644369, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20644369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322183 + 10322184.

It is an arithmetic number, because the mean of its divisors is an integer number (10322184).

Almost surely, 2^20644367 is an apocalyptic number.

20644367 is a deficient number, since it is larger than the sum of its proper divisors (1).

20644367 is an equidigital number, since it uses as much as digits as its factorization.

20644367 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 32.

The square root of 20644367 is about 4543.6072673593. The cubic root of 20644367 is about 274.3261385448.

Adding to 20644367 its reverse (76344602), we get a palindrome (96988969).

The spelling of 20644367 in words is "twenty million, six hundred forty-four thousand, three hundred sixty-seven".