20019819 has 4 divisors (see below), whose sum is σ = 26693096. Its totient is φ = 13346544.

The previous prime is 20019817. The next prime is 20019827. The reversal of 20019819 is 91891002.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20019819 - 2¹ = 20019817 is a prime.

It is a super-2 number, since 2×20019819² = 801586305585522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20019817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3336634 + ... + 3336639.

It is an arithmetic number, because the mean of its divisors is an integer number (6673274).

Almost surely, 2^20019819 is an apocalyptic number.

20019819 is a deficient number, since it is larger than the sum of its proper divisors (6673277).

20019819 is an equidigital number, since it uses as much as digits as its factorization.

20019819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6673276.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 20019819 is about 4474.3512378891. The cubic root of 20019819 is about 271.5313937969.

The spelling of 20019819 in words is "twenty million, nineteen thousand, eight hundred nineteen".