31205213 has 8 divisors (see below), whose sum is σ = 33737088. Its totient is φ = 28692144.

The previous prime is 31205203. The next prime is 31205231. The reversal of 31205213 is 31250213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31205213 - 2¹⁰ = 31204189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31205191 and 31205200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31205203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1145 + ... + 7982.

It is an arithmetic number, because the mean of its divisors is an integer number (4217136).

Almost surely, 2^31205213 is an apocalyptic number.

It is an amenable number.

31205213 is a deficient number, since it is larger than the sum of its proper divisors (2531875).

31205213 is a wasteful number, since it uses less digits than its factorization.

31205213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9403.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 31205213 is about 5586.1626363721. The cubic root of 31205213 is about 314.8297156395.

Adding to 31205213 its reverse (31250213), we get a palindrome (62455426).

The spelling of 31205213 in words is "thirty-one million, two hundred five thousand, two hundred thirteen".