213243431 has 4 divisors (see below), whose sum is σ = 213274152. Its totient is φ = 213212712.

The previous prime is 213243413. The next prime is 213243449. The reversal of 213243431 is 134342312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (213243413) and next prime (213243449).

It is a cyclic number.

It is not a de Polignac number, because 213243431 - 2⁶ = 213243367 is a prime.

It is a super-2 number, since 2×213243431² = 90945521729303522, 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 = 213243397 and 213243406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213249431) 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, 536 + ... + 20658.

It is an arithmetic number, because the mean of its divisors is an integer number (53318538).

Almost surely, 2^213243431 is an apocalyptic number.

213243431 is a deficient number, since it is larger than the sum of its proper divisors (30721).

213243431 is a wasteful number, since it uses less digits than its factorization.

213243431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30720.

The product of its digits is 1728, while the sum is 23.

The square root of 213243431 is about 14602.8569465019. The cubic root of 213243431 is about 597.4366859261.

Adding to 213243431 its reverse (134342312), we get a palindrome (347585743).

The spelling of 213243431 in words is "two hundred thirteen million, two hundred forty-three thousand, four hundred thirty-one".