28820417 has 4 divisors (see below), whose sum is σ = 29523396. Its totient is φ = 28117440.

The previous prime is 28820413. The next prime is 28820431. The reversal of 28820417 is 71402882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71402882 = 2 ⋅35701441.

It can be written as a sum of positive squares in 2 ways, for example, as 4456321 + 24364096 = 2111^2 + 4936^2 .

It is a cyclic number.

It is not a de Polignac number, because 28820417 - 2² = 28820413 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28820411) 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, 351428 + ... + 351509.

It is an arithmetic number, because the mean of its divisors is an integer number (7380849).

Almost surely, 2^28820417 is an apocalyptic number.

It is an amenable number.

28820417 is a deficient number, since it is larger than the sum of its proper divisors (702979).

28820417 is an equidigital number, since it uses as much as digits as its factorization.

28820417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 702978.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 28820417 is about 5368.4650506453. The cubic root of 28820417 is about 306.5961898274.

The spelling of 28820417 in words is "twenty-eight million, eight hundred twenty thousand, four hundred seventeen".