213431 has 4 divisors (see below), whose sum is σ = 217512. Its totient is φ = 209352.

The previous prime is 213407. The next prime is 213449. The reversal of 213431 is 134312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213431 is a prime.

It is a super-2 number, since 2×213431² = 91105583522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213461) 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, 1961 + ... + 2066.

It is an arithmetic number, because the mean of its divisors is an integer number (54378).

2²¹³⁴³¹ is an apocalyptic number.

213431 is a deficient number, since it is larger than the sum of its proper divisors (4081).

213431 is an equidigital number, since it uses as much as digits as its factorization.

213431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4080.

The product of its digits is 72, while the sum is 14.

The square root of 213431 is about 461.9859305217. The cubic root of 213431 is about 59.7611803101.

Adding to 213431 its reverse (134312), we get a palindrome (347743).

It can be divided in two parts, 2 and 13431, that multiplied together give a palindrome (26862).

The spelling of 213431 in words is "two hundred thirteen thousand, four hundred thirty-one".