21852017 has 4 divisors (see below), whose sum is σ = 23838576. Its totient is φ = 19865460.

The previous prime is 21852013. The next prime is 21852029. The reversal of 21852017 is 71025812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21852017 - 2² = 21852013 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21852011) 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, 993263 + ... + 993284.

It is an arithmetic number, because the mean of its divisors is an integer number (5959644).

Almost surely, 2^21852017 is an apocalyptic number.

It is an amenable number.

21852017 is a deficient number, since it is larger than the sum of its proper divisors (1986559).

21852017 is a wasteful number, since it uses less digits than its factorization.

21852017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1986558.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 21852017 is about 4674.6141017201. The cubic root of 21852017 is about 279.5742551867.

Adding to 21852017 its reverse (71025812), we get a palindrome (92877829).

The spelling of 21852017 in words is "twenty-one million, eight hundred fifty-two thousand, seventeen".