20684479 has 2 divisors, whose sum is σ = 20684480. Its totient is φ = 20684478.

The previous prime is 20684473. The next prime is 20684509. The reversal of 20684479 is 97448602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20684479 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20684473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10342239 + 10342240.

It is an arithmetic number, because the mean of its divisors is an integer number (10342240).

Almost surely, 2^20684479 is an apocalyptic number.

20684479 is a deficient number, since it is larger than the sum of its proper divisors (1).

20684479 is an equidigital number, since it uses as much as digits as its factorization.

20684479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 20684479 is about 4548.0192391853. The cubic root of 20684479 is about 274.5036954700.

The spelling of 20684479 in words is "twenty million, six hundred eighty-four thousand, four hundred seventy-nine".