20028217 has 4 divisors (see below), whose sum is σ = 21848976. Its totient is φ = 18207460.

The previous prime is 20028209. The next prime is 20028221. The reversal of 20028217 is 71282002.

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 20028217 - 2³ = 20028209 is a prime.

It is a super-2 number, since 2×20028217² = 802258952398178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20028257) 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, 910363 + ... + 910384.

It is an arithmetic number, because the mean of its divisors is an integer number (5462244).

Almost surely, 2^20028217 is an apocalyptic number.

It is an amenable number.

20028217 is a deficient number, since it is larger than the sum of its proper divisors (1820759).

20028217 is a wasteful number, since it uses less digits than its factorization.

20028217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1820758.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 20028217 is about 4475.2895995678. The cubic root of 20028217 is about 271.5693562092.

The spelling of 20028217 in words is "twenty million, twenty-eight thousand, two hundred seventeen".