21361343 has 4 divisors (see below), whose sum is σ = 21397488. Its totient is φ = 21325200.

The previous prime is 21361303. The next prime is 21361391. The reversal of 21361343 is 34316312.

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

It is a cyclic number.

It is not a de Polignac number, because 21361343 - 2¹⁰ = 21360319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361303) 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, 17171 + ... + 18372.

It is an arithmetic number, because the mean of its divisors is an integer number (5349372).

Almost surely, 2^21361343 is an apocalyptic number.

21361343 is a deficient number, since it is larger than the sum of its proper divisors (36145).

21361343 is an equidigital number, since it uses as much as digits as its factorization.

21361343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36144.

The product of its digits is 1296, while the sum is 23.

The square root of 21361343 is about 4621.8332942675. The cubic root of 21361343 is about 277.4658367704.

Adding to 21361343 its reverse (34316312), we get a palindrome (55677655).

The spelling of 21361343 in words is "twenty-one million, three hundred sixty-one thousand, three hundred forty-three".