20398 has 16 divisors (see below), whose sum is σ = 36864. Its totient is φ = 8280.

The previous prime is 20393. The next prime is 20399. The reversal of 20398 is 89302.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20393) by changing a digit.

20398 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 411 + ... + 457.

It is an arithmetic number, because the mean of its divisors is an integer number (2304).

2²⁰³⁹⁸ is an apocalyptic number.

20398 is a deficient number, since it is larger than the sum of its proper divisors (16466).

20398 is a wasteful number, since it uses less digits than its factorization.

20398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 20398 is about 142.8215669988. The cubic root of 20398 is about 27.3230511924.

The spelling of 20398 in words is "twenty thousand, three hundred ninety-eight".