20308 has 6 divisors (see below), whose sum is σ = 35546. Its totient is φ = 10152.

The previous prime is 20297. The next prime is 20323. The reversal of 20308 is 80302.

It can be written as a sum of positive squares in only one way, i.e., 20164 + 144 = 142^2 + 12^2 .

It is a nialpdrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2535 + ... + 2542.

2²⁰³⁰⁸ is an apocalyptic number.

It is an amenable number.

20308 is a deficient number, since it is larger than the sum of its proper divisors (15238).

20308 is a wasteful number, since it uses less digits than its factorization.

20308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5081 (or 5079 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20308 is about 142.5061402186. The cubic root of 20308 is about 27.2828070485.

The spelling of 20308 in words is "twenty thousand, three hundred eight".