213009311 has 4 divisors (see below), whose sum is σ = 217541472. Its totient is φ = 208477152.

The previous prime is 213009283. The next prime is 213009317. The reversal of 213009311 is 113900312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213009311 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 (213009317) 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, 2266010 + ... + 2266103.

It is an arithmetic number, because the mean of its divisors is an integer number (54385368).

Almost surely, 2^213009311 is an apocalyptic number.

213009311 is a deficient number, since it is larger than the sum of its proper divisors (4532161).

213009311 is an equidigital number, since it uses as much as digits as its factorization.

213009311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4532160.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 213009311 is about 14594.8385054443. The cubic root of 213009311 is about 597.2179639144.

Adding to 213009311 its reverse (113900312), we get a palindrome (326909623).

The spelling of 213009311 in words is "two hundred thirteen million, nine thousand, three hundred eleven".