213311431 has 4 divisors (see below), whose sum is σ = 213706264. Its totient is φ = 212916600.

The previous prime is 213311429. The next prime is 213311437. The reversal of 213311431 is 134113312.

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 213311431 - 2¹ = 213311429 is a prime.

It is a super-2 number, since 2×213311431² = 91003533190535522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213311399 and 213311408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213311437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196605 + ... + 197686.

It is an arithmetic number, because the mean of its divisors is an integer number (53426566).

Almost surely, 2^213311431 is an apocalyptic number.

213311431 is a deficient number, since it is larger than the sum of its proper divisors (394833).

213311431 is an equidigital number, since it uses as much as digits as its factorization.

213311431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394832.

The product of its digits is 216, while the sum is 19.

The square root of 213311431 is about 14605.1850724323. The cubic root of 213311431 is about 597.5001835868.

Adding to 213311431 its reverse (134113312), we get a palindrome (347424743).

It can be divided in two parts, 2133114 and 31, that added together give a triangular number (2133145 = T₂₀₆₅).

The spelling of 213311431 in words is "two hundred thirteen million, three hundred eleven thousand, four hundred thirty-one".