20217889 has 4 divisors (see below), whose sum is σ = 20502720. Its totient is φ = 19933060.

The previous prime is 20217839. The next prime is 20217931. The reversal of 20217889 is 98871202.

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 20217889 - 2⁷ = 20217761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20217829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142309 + ... + 142450.

It is an arithmetic number, because the mean of its divisors is an integer number (5125680).

Almost surely, 2^20217889 is an apocalyptic number.

It is an amenable number.

20217889 is a deficient number, since it is larger than the sum of its proper divisors (284831).

20217889 is an equidigital number, since it uses as much as digits as its factorization.

20217889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284830.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 20217889 is about 4496.4306955629. The cubic root of 20217889 is about 272.4239397181.

The spelling of 20217889 in words is "twenty million, two hundred seventeen thousand, eight hundred eighty-nine".