213021311 has 4 divisors (see below), whose sum is σ = 213157800. Its totient is φ = 212884824.

The previous prime is 213021307. The next prime is 213021317. The reversal of 213021311 is 113120312.

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 213021311 - 2² = 213021307 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 (213021317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65876 + ... + 69033.

It is an arithmetic number, because the mean of its divisors is an integer number (53289450).

Almost surely, 2^213021311 is an apocalyptic number.

213021311 is a deficient number, since it is larger than the sum of its proper divisors (136489).

213021311 is a wasteful number, since it uses less digits than its factorization.

213021311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136488.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 213021311 is about 14595.2496038951. The cubic root of 213021311 is about 597.2291785744.

Adding to 213021311 its reverse (113120312), we get a palindrome (326141623).

Subtracting from 213021311 its reverse (113120312), we obtain a palindrome (99900999).

The spelling of 213021311 in words is "two hundred thirteen million, twenty-one thousand, three hundred eleven".