213663 has 8 divisors (see below), whose sum is σ = 289408. Its totient is φ = 140184.

The previous prime is 213659. The next prime is 213713. The reversal of 213663 is 366312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 213663 - 2² = 213659 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213663.

It is not an unprimeable number, because it can be changed into a prime (213613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 331 + ... + 732.

It is an arithmetic number, because the mean of its divisors is an integer number (36176).

2²¹³⁶⁶³ is an apocalyptic number.

213663 is a deficient number, since it is larger than the sum of its proper divisors (75745).

213663 is a wasteful number, since it uses less digits than its factorization.

213663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133.

The product of its digits is 648, while the sum is 21.

The square root of 213663 is about 462.2369522226. The cubic root of 213663 is about 59.7828259836.

Adding to 213663 its reverse (366312), we get a palindrome (579975).

The spelling of 213663 in words is "two hundred thirteen thousand, six hundred sixty-three".