21446321 has 8 divisors (see below), whose sum is σ = 23659944. Its totient is φ = 19313280.

The previous prime is 21446317. The next prime is 21446329. The reversal of 21446321 is 12364412.

It can be written as a sum of positive squares in 4 ways, for example, as 55696 + 21390625 = 236^2 + 4625^2 .

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 21446321 - 2² = 21446317 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 (21446329) 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, 19586 + ... + 20651.

It is an arithmetic number, because the mean of its divisors is an integer number (2957493).

Almost surely, 2^21446321 is an apocalyptic number.

It is an amenable number.

21446321 is a deficient number, since it is larger than the sum of its proper divisors (2213623).

21446321 is a wasteful number, since it uses less digits than its factorization.

21446321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40291.

The product of its digits is 1152, while the sum is 23.

The square root of 21446321 is about 4631.0172748544. The cubic root of 21446321 is about 277.8332808143.

The spelling of 21446321 in words is "twenty-one million, four hundred forty-six thousand, three hundred twenty-one".