20644079 has 2 divisors, whose sum is σ = 20644080. Its totient is φ = 20644078.

The previous prime is 20644049. The next prime is 20644081. The reversal of 20644079 is 97044602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20644079 is a prime.

Together with 20644081, 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 (20644049) 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, 10322039 + 10322040.

It is an arithmetic number, because the mean of its divisors is an integer number (10322040).

Almost surely, 2^20644079 is an apocalyptic number.

20644079 is a deficient number, since it is larger than the sum of its proper divisors (1).

20644079 is an equidigital number, since it uses as much as digits as its factorization.

20644079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20644079 is about 4543.5755743687. The cubic root of 20644079 is about 274.3248628733.

The spelling of 20644079 in words is "twenty million, six hundred forty-four thousand, seventy-nine".