21596017 has 4 divisors (see below), whose sum is σ = 21618676. Its totient is φ = 21573360.

The previous prime is 21595997. The next prime is 21596021. The reversal of 21596017 is 71069512.

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 13075456 + 8520561 = 3616^2 + 2919^2 .

It is a cyclic number.

It is not a de Polignac number, because 21596017 - 2¹⁵ = 21563249 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 21596017.

It is not an unprimeable number, because it can be changed into a prime (21596087) 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, 9834 + ... + 11827.

It is an arithmetic number, because the mean of its divisors is an integer number (5404669).

Almost surely, 2^21596017 is an apocalyptic number.

It is an amenable number.

21596017 is a deficient number, since it is larger than the sum of its proper divisors (22659).

21596017 is an equidigital number, since it uses as much as digits as its factorization.

21596017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22658.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 21596017 is about 4647.1514931192. The cubic root of 21596017 is about 278.4782109568.

The spelling of 21596017 in words is "twenty-one million, five hundred ninety-six thousand, seventeen".