213021111 has 4 divisors (see below), whose sum is σ = 284028152. Its totient is φ = 142014072.

The previous prime is 213021079. The next prime is 213021157. The reversal of 213021111 is 111120312.

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

It is not a de Polignac number, because 213021111 - 2⁵ = 213021079 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 (213021161) 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, 35503516 + ... + 35503521.

It is an arithmetic number, because the mean of its divisors is an integer number (71007038).

Almost surely, 2^213021111 is an apocalyptic number.

213021111 is a deficient number, since it is larger than the sum of its proper divisors (71007041).

213021111 is an equidigital number, since it uses as much as digits as its factorization.

213021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71007040.

The product of its (nonzero) digits is 12, while the sum is 12.

The square root of 213021111 is about 14595.2427523491. The cubic root of 213021111 is about 597.2289916669.

Adding to 213021111 its reverse (111120312), we get a palindrome (324141423).

The spelling of 213021111 in words is "two hundred thirteen million, twenty-one thousand, one hundred eleven".