20644319 has 2 divisors, whose sum is σ = 20644320. Its totient is φ = 20644318.

The previous prime is 20644303. The next prime is 20644331. The reversal of 20644319 is 91344602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20644319 - 2⁴ = 20644303 is a prime.

It is a super-2 number, since 2×20644319² = 852375813947522, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1308827 and since 20644319 and 1308827 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 20644291 and 20644300.

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 polite number, since it can be written as a sum of consecutive naturals, namely, 10322159 + 10322160.

It is an arithmetic number, because the mean of its divisors is an integer number (10322160).

Almost surely, 2^20644319 is an apocalyptic number.

20644319 is a deficient number, since it is larger than the sum of its proper divisors (1).

20644319 is an equidigital number, since it uses as much as digits as its factorization.

20644319 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20644319 is about 4543.6019852095. The cubic root of 20644319 is about 274.3259259337.

The spelling of 20644319 in words is "twenty million, six hundred forty-four thousand, three hundred nineteen".