21084193 has 4 divisors (see below), whose sum is σ = 22706068. Its totient is φ = 19462320.

The previous prime is 21084187. The next prime is 21084227. The reversal of 21084193 is 39148012.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 861184 + 20223009 = 928^2 + 4497^2 .

It is a cyclic number.

It is not a de Polignac number, because 21084193 - 2²¹ = 18987041 is a prime.

It is a super-2 number, since 2×21084193² = 889086388922498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21084103) 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, 810918 + ... + 810943.

It is an arithmetic number, because the mean of its divisors is an integer number (5676517).

Almost surely, 2^21084193 is an apocalyptic number.

It is an amenable number.

21084193 is a deficient number, since it is larger than the sum of its proper divisors (1621875).

21084193 is a wasteful number, since it uses less digits than its factorization.

21084193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1621874.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 21084193 is about 4591.7527154672. The cubic root of 21084193 is about 276.2606277519.

The spelling of 21084193 in words is "twenty-one million, eighty-four thousand, one hundred ninety-three".