21196393 has 4 divisors (see below), whose sum is σ = 21275460. Its totient is φ = 21117328.

The previous prime is 21196349. The next prime is 21196397. The reversal of 21196393 is 39369112.

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 8714304 + 12482089 = 2952^2 + 3533^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21196393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21196397) 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 3 ways as a sum of consecutive naturals, for example, 39130 + ... + 39667.

It is an arithmetic number, because the mean of its divisors is an integer number (5318865).

Almost surely, 2^21196393 is an apocalyptic number.

It is an amenable number.

21196393 is a deficient number, since it is larger than the sum of its proper divisors (79067).

21196393 is an equidigital number, since it uses as much as digits as its factorization.

21196393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79066.

The product of its digits is 8748, while the sum is 34.

The square root of 21196393 is about 4603.9540614563. The cubic root of 21196393 is about 276.7498034053.

The spelling of 21196393 in words is "twenty-one million, one hundred ninety-six thousand, three hundred ninety-three".