213808 has 40 divisors (see below), whose sum is σ = 499968. Its totient is φ = 86592.

The previous prime is 213799. The next prime is 213821. The reversal of 213808 is 808312.

It is a congruent number.

It is an unprimeable number.

213808 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2535 + ... + 2617.

2²¹³⁸⁰⁸ is an apocalyptic number.

213808 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249984).

213808 is an abundant number, since it is smaller than the sum of its proper divisors (286160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

213808 is a wasteful number, since it uses less digits than its factorization.

213808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 213808 is about 462.3937715843. The cubic root of 213808 is about 59.7963465738.

The spelling of 213808 in words is "two hundred thirteen thousand, eight hundred eight".