21238193 has 4 divisors (see below), whose sum is σ = 21923328. Its totient is φ = 20553060.

The previous prime is 21238157. The next prime is 21238207. The reversal of 21238193 is 39183212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21238193 - 2¹² = 21234097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21238103) 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, 342521 + ... + 342582.

It is an arithmetic number, because the mean of its divisors is an integer number (5480832).

Almost surely, 2^21238193 is an apocalyptic number.

It is an amenable number.

21238193 is a deficient number, since it is larger than the sum of its proper divisors (685135).

21238193 is an equidigital number, since it uses as much as digits as its factorization.

21238193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685134.

The product of its digits is 2592, while the sum is 29.

The square root of 21238193 is about 4608.4914017496. The cubic root of 21238193 is about 276.9316039259.

The spelling of 21238193 in words is "twenty-one million, two hundred thirty-eight thousand, one hundred ninety-three".