213863 has 4 divisors (see below), whose sum is σ = 230328. Its totient is φ = 197400.

The previous prime is 213859. The next prime is 213881. The reversal of 213863 is 368312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 213863 - 2² = 213859 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213833) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8213 + ... + 8238.

It is an arithmetic number, because the mean of its divisors is an integer number (57582).

2²¹³⁸⁶³ is an apocalyptic number.

213863 is a deficient number, since it is larger than the sum of its proper divisors (16465).

213863 is a wasteful number, since it uses less digits than its factorization.

213863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16464.

The product of its digits is 864, while the sum is 23.

The square root of 213863 is about 462.4532408796. The cubic root of 213863 is about 59.8014734744.

Subtracting 213863 from its reverse (368312), we obtain a square (154449 = 393²).

The spelling of 213863 in words is "two hundred thirteen thousand, eight hundred sixty-three".