21322865 has 8 divisors (see below), whose sum is σ = 25631208. Its totient is φ = 17029120.

The previous prime is 21322849. The next prime is 21322871. The reversal of 21322865 is 56822312.

It can be written as a sum of positive squares in 4 ways, for example, as 1216609 + 20106256 = 1103^2 + 4484^2 .

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

It is not a de Polignac number, because 21322865 - 2⁴ = 21322849 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122 + ... + 6531.

It is an arithmetic number, because the mean of its divisors is an integer number (3203901).

Almost surely, 2^21322865 is an apocalyptic number.

It is an amenable number.

21322865 is a deficient number, since it is larger than the sum of its proper divisors (4308343).

21322865 is an equidigital number, since it uses as much as digits as its factorization.

21322865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7299.

The product of its digits is 5760, while the sum is 29.

The square root of 21322865 is about 4617.6687841377. The cubic root of 21322865 is about 277.2991377122.

The spelling of 21322865 in words is "twenty-one million, three hundred twenty-two thousand, eight hundred sixty-five".