213005 has 16 divisors (see below), whose sum is σ = 287280. Its totient is φ = 150528.

The previous prime is 212999. The next prime is 213019. The reversal of 213005 is 500312.

It can be written as a sum of positive squares in 8 ways, for example, as 64009 + 148996 = 253^2 + 386^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213005 is a prime.

It is a super-2 number, since 2×213005² = 90742260050, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1829 + ... + 1941.

It is an arithmetic number, because the mean of its divisors is an integer number (17955).

2²¹³⁰⁰⁵ is an apocalyptic number.

213005 is the 377-th pentagonal number.

It is an amenable number.

213005 is a deficient number, since it is larger than the sum of its proper divisors (74275).

213005 is a wasteful number, since it uses less digits than its factorization.

213005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160.

The product of its (nonzero) digits is 30, while the sum is 11.

The square root of 213005 is about 461.5246472292. The cubic root of 213005 is about 59.7213934945.

Adding to 213005 its reverse (500312), we get a palindrome (713317).

The spelling of 213005 in words is "two hundred thirteen thousand, five".