21134321 has 4 divisors (see below), whose sum is σ = 22760052. Its totient is φ = 19508592.

The previous prime is 21134293. The next prime is 21134353. The reversal of 21134321 is 12343112.

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 929296 + 20205025 = 964^2 + 4495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21134321 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21134321.

It is not an unprimeable number, because it can be changed into a prime (21134021) 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, 812846 + ... + 812871.

It is an arithmetic number, because the mean of its divisors is an integer number (5690013).

Almost surely, 2^21134321 is an apocalyptic number.

It is an amenable number.

21134321 is a deficient number, since it is larger than the sum of its proper divisors (1625731).

21134321 is a wasteful number, since it uses less digits than its factorization.

21134321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1625730.

The product of its digits is 144, while the sum is 17.

The square root of 21134321 is about 4597.2079570104. The cubic root of 21134321 is about 276.4793924650.

Adding to 21134321 its reverse (12343112), we get a palindrome (33477433).

The spelling of 21134321 in words is "twenty-one million, one hundred thirty-four thousand, three hundred twenty-one".