20398217 has 32 divisors (see below), whose sum is σ = 25903104. Its totient is φ = 15681600.

The previous prime is 20398207. The next prime is 20398219. The reversal of 20398217 is 71289302.

It is a cyclic number.

It is not a de Polignac number, because 20398217 - 2⁸ = 20397961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20398219) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 304418 + ... + 304484.

It is an arithmetic number, because the mean of its divisors is an integer number (809472).

Almost surely, 2^20398217 is an apocalyptic number.

It is an amenable number.

20398217 is a deficient number, since it is larger than the sum of its proper divisors (5504887).

20398217 is a wasteful number, since it uses less digits than its factorization.

20398217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20398217 is about 4516.4385305238. The cubic root of 20398217 is about 273.2314808232.

The spelling of 20398217 in words is "twenty million, three hundred ninety-eight thousand, two hundred seventeen".