213111331 has 4 divisors (see below), whose sum is σ = 213255000. Its totient is φ = 212967664.

The previous prime is 213111323. The next prime is 213111359. The reversal of 213111331 is 133111312.

213111331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 213111331 - 2³ = 213111323 is a prime.

It is a super-2 number, since 2×213111331² = 90832878801183122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213111131) 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, 69586 + ... + 72583.

It is an arithmetic number, because the mean of its divisors is an integer number (53313750).

Almost surely, 2^213111331 is an apocalyptic number.

213111331 is a deficient number, since it is larger than the sum of its proper divisors (143669).

213111331 is a wasteful number, since it uses less digits than its factorization.

213111331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143668.

The product of its digits is 54, while the sum is 16.

The square root of 213111331 is about 14598.3331582753. Note that the first 3 decimals coincide. The cubic root of 213111331 is about 597.3132937882.

Adding to 213111331 its reverse (133111312), we get a palindrome (346222643).

The spelling of 213111331 in words is "two hundred thirteen million, one hundred eleven thousand, three hundred thirty-one".