28217001 has 4 divisors (see below), whose sum is σ = 37622672. Its totient is φ = 18811332.

The previous prime is 28216973. The next prime is 28217011. The reversal of 28217001 is 10071282.

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 not a de Polignac number, because 28217001 - 2¹⁷ = 28085929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28217011) 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, 4702831 + ... + 4702836.

It is an arithmetic number, because the mean of its divisors is an integer number (9405668).

Almost surely, 2^28217001 is an apocalyptic number.

It is an amenable number.

28217001 is a deficient number, since it is larger than the sum of its proper divisors (9405671).

28217001 is an equidigital number, since it uses as much as digits as its factorization.

28217001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9405670.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 28217001 is about 5311.9677145103. The cubic root of 28217001 is about 304.4413351141.

Adding to 28217001 its reverse (10071282), we get a palindrome (38288283).

The spelling of 28217001 in words is "twenty-eight million, two hundred seventeen thousand, one".