20828317 has 6 divisors (see below), whose sum is σ = 21773822. Its totient is φ = 19922232.

The previous prime is 20828309. The next prime is 20828323. The reversal of 20828317 is 71382802.

It can be written as a sum of positive squares in only one way, i.e., 20738916 + 89401 = 4554^2 + 299^2 .

It is not a de Polignac number, because 20828317 - 2³ = 20828309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20828387) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19158 + ... + 20215.

Almost surely, 2^20828317 is an apocalyptic number.

It is an amenable number.

20828317 is a deficient number, since it is larger than the sum of its proper divisors (945505).

20828317 is an equidigital number, since it uses as much as digits as its factorization.

20828317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39419 (or 39396 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 20828317 is about 4563.8051010095. The cubic root of 20828317 is about 275.1385175448.

The spelling of 20828317 in words is "twenty million, eight hundred twenty-eight thousand, three hundred seventeen".