20817001 has 4 divisors (see below), whose sum is σ = 21722112. Its totient is φ = 19911892.

The previous prime is 20816953. The next prime is 20817037. The reversal of 20817001 is 10071802.

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 20817001 - 2⁹ = 20816489 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 20817001.

It is not an unprimeable number, because it can be changed into a prime (20817091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 452521 + ... + 452566.

It is an arithmetic number, because the mean of its divisors is an integer number (5430528).

Almost surely, 2^20817001 is an apocalyptic number.

It is an amenable number.

20817001 is a deficient number, since it is larger than the sum of its proper divisors (905111).

20817001 is an equidigital number, since it uses as much as digits as its factorization.

20817001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905110.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 20817001 is about 4562.5651776166. The cubic root of 20817001 is about 275.0886810412.

Adding to 20817001 its reverse (10071802), we get a palindrome (30888803).

The spelling of 20817001 in words is "twenty million, eight hundred seventeen thousand, one".