20890019 has 2 divisors, whose sum is σ = 20890020. Its totient is φ = 20890018.

The previous prime is 20889943. The next prime is 20890027. The reversal of 20890019 is 91009802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20890019 - 2⁸ = 20889763 is a prime.

It is a super-2 number, since 2×20890019² = 872785787640722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20889973 and 20890000.

It is not a weakly prime, because it can be changed into another prime (20890099) 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, 10445009 + 10445010.

It is an arithmetic number, because the mean of its divisors is an integer number (10445010).

Almost surely, 2^20890019 is an apocalyptic number.

20890019 is a deficient number, since it is larger than the sum of its proper divisors (1).

20890019 is an equidigital number, since it uses as much as digits as its factorization.

20890019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 20890019 is about 4570.5600313310. The cubic root of 20890019 is about 275.4099406666.

The spelling of 20890019 in words is "twenty million, eight hundred ninety thousand, nineteen".