21373219 has 4 divisors (see below), whose sum is σ = 24426544. Its totient is φ = 18319896.

The previous prime is 21373207. The next prime is 21373223. The reversal of 21373219 is 91237312.

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

It is not a de Polignac number, because 21373219 - 2¹¹ = 21371171 is a prime.

It is a super-2 number, since 2×21373219² = 913628980843922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21373249) 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, 1526652 + ... + 1526665.

It is an arithmetic number, because the mean of its divisors is an integer number (6106636).

Almost surely, 2^21373219 is an apocalyptic number.

21373219 is a deficient number, since it is larger than the sum of its proper divisors (3053325).

21373219 is an equidigital number, since it uses as much as digits as its factorization.

21373219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3053324.

The product of its digits is 2268, while the sum is 28.

The square root of 21373219 is about 4623.1178873137. The cubic root of 21373219 is about 277.5172469869.

It can be divided in two parts, 2137 and 3219, that added together give a triangular number (5356 = T₁₀₃).

The spelling of 21373219 in words is "twenty-one million, three hundred seventy-three thousand, two hundred nineteen".