20605019 has 2 divisors, whose sum is σ = 20605020. Its totient is φ = 20605018.

The previous prime is 20604973. The next prime is 20605021. The reversal of 20605019 is 91050602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20605019 is a prime.

It is a super-2 number, since 2×20605019² = 849133615980722, which contains 22 as substring.

Together with 20605021, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20604985 and 20605003.

It is not a weakly prime, because it can be changed into another prime (20605069) 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, 10302509 + 10302510.

It is an arithmetic number, because the mean of its divisors is an integer number (10302510).

Almost surely, 2^20605019 is an apocalyptic number.

20605019 is a deficient number, since it is larger than the sum of its proper divisors (1).

20605019 is an equidigital number, since it uses as much as digits as its factorization.

20605019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 20605019 is about 4539.2751624020. The cubic root of 20605019 is about 274.1517398812.

The spelling of 20605019 in words is "twenty million, six hundred five thousand, nineteen".