21095321 has 8 divisors (see below), whose sum is σ = 23030280. Its totient is φ = 19204992.

The previous prime is 21095311. The next prime is 21095357. The reversal of 21095321 is 12359012.

It can be written as a sum of positive squares in 4 ways, for example, as 265225 + 20830096 = 515^2 + 4564^2 .

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-21095321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21095311) 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, 10166 + ... + 12063.

It is an arithmetic number, because the mean of its divisors is an integer number (2878785).

Almost surely, 2^21095321 is an apocalyptic number.

It is an amenable number.

21095321 is a deficient number, since it is larger than the sum of its proper divisors (1934959).

21095321 is a wasteful number, since it uses less digits than its factorization.

21095321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22315.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 21095321 is about 4592.9642933513. The cubic root of 21095321 is about 276.3092216215.

The spelling of 21095321 in words is "twenty-one million, ninety-five thousand, three hundred twenty-one".