21230019 has 20 divisors (see below), whose sum is σ = 31847200. Its totient is φ = 14094000.

The previous prime is 21230017. The next prime is 21230023. The reversal of 21230019 is 91003212.

It is a happy number.

It is not a de Polignac number, because 21230019 - 2¹ = 21230017 is a prime.

It is a super-2 number, since 2×21230019² = 901427413480722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21229983 and 21230010.

It is not an unprimeable number, because it can be changed into a prime (21230017) 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 in 19 ways as a sum of consecutive naturals, for example, 27894 + ... + 28644.

It is an arithmetic number, because the mean of its divisors is an integer number (1592360).

Almost surely, 2^21230019 is an apocalyptic number.

21230019 is a deficient number, since it is larger than the sum of its proper divisors (10617181).

21230019 is an equidigital number, since it uses as much as digits as its factorization.

21230019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1112 (or 1103 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 21230019 is about 4607.6044752127. The cubic root of 21230019 is about 276.8960715653.

The spelling of 21230019 in words is "twenty-one million, two hundred thirty thousand, nineteen".