21254321 has 8 divisors (see below), whose sum is σ = 23220000. Its totient is φ = 19294240.

The previous prime is 21254309. The next prime is 21254327. The reversal of 21254321 is 12345212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21254321 is a prime.

It is a super-2 number, since 2×21254321² = 903492322342082, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21254293 and 21254302.

It is not an unprimeable number, because it can be changed into a prime (21254327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13430 + ... + 14928.

It is an arithmetic number, because the mean of its divisors is an integer number (2902500).

Almost surely, 2^21254321 is an apocalyptic number.

It is an amenable number.

21254321 is a deficient number, since it is larger than the sum of its proper divisors (1965679).

21254321 is a wasteful number, since it uses less digits than its factorization.

21254321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2799.

The product of its digits is 480, while the sum is 20.

The square root of 21254321 is about 4610.2408830776. The cubic root of 21254321 is about 277.0016855758.

Adding to 21254321 its reverse (12345212), we get a palindrome (33599533).

It can be divided in two parts, 2125 and 4321, that added together give a palindrome (6446).

The spelling of 21254321 in words is "twenty-one million, two hundred fifty-four thousand, three hundred twenty-one".