21036193 has 4 divisors (see below), whose sum is σ = 21222468. Its totient is φ = 20849920.

The previous prime is 21036187. The next prime is 21036203. The reversal of 21036193 is 39163012.

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 10942864 + 10093329 = 3308^2 + 3177^2 .

It is a cyclic number.

It is not a de Polignac number, because 21036193 - 2¹³ = 21028001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21036133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92968 + ... + 93193.

It is an arithmetic number, because the mean of its divisors is an integer number (5305617).

Almost surely, 2^21036193 is an apocalyptic number.

It is an amenable number.

21036193 is a deficient number, since it is larger than the sum of its proper divisors (186275).

21036193 is a wasteful number, since it uses less digits than its factorization.

21036193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186274.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 21036193 is about 4586.5229749779. The cubic root of 21036193 is about 276.0508246737.

The spelling of 21036193 in words is "twenty-one million, thirty-six thousand, one hundred ninety-three".