21291353 has 8 divisors (see below), whose sum is σ = 22284288. Its totient is φ = 20304064.

The previous prime is 21291337. The next prime is 21291359. The reversal of 21291353 is 35319212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21291353 - 2⁴ = 21291337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21291359) 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 7 ways as a sum of consecutive naturals, for example, 7601 + ... + 10017.

It is an arithmetic number, because the mean of its divisors is an integer number (2785536).

Almost surely, 2^21291353 is an apocalyptic number.

21291353 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21291353 is a deficient number, since it is larger than the sum of its proper divisors (992935).

21291353 is a wasteful number, since it uses less digits than its factorization.

21291353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2823.

The product of its digits is 1620, while the sum is 26.

The square root of 21291353 is about 4614.2554112229. The cubic root of 21291353 is about 277.1624681703.

The spelling of 21291353 in words is "twenty-one million, two hundred ninety-one thousand, three hundred fifty-three".