31828213 has 4 divisors (see below), whose sum is σ = 32568448. Its totient is φ = 31087980.

The previous prime is 31828207. The next prime is 31828217. The reversal of 31828213 is 31282813.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31828213 - 2¹³ = 31820021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31828217) 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, 370053 + ... + 370138.

It is an arithmetic number, because the mean of its divisors is an integer number (8142112).

Almost surely, 2^31828213 is an apocalyptic number.

It is an amenable number.

31828213 is a deficient number, since it is larger than the sum of its proper divisors (740235).

31828213 is an equidigital number, since it uses as much as digits as its factorization.

31828213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740234.

The product of its digits is 2304, while the sum is 28.

The square root of 31828213 is about 5641.6498473408. The cubic root of 31828213 is about 316.9110764388.

It can be divided in two parts, 31828 and 213, that added together give a square (32041 = 179²).

The spelling of 31828213 in words is "thirty-one million, eight hundred twenty-eight thousand, two hundred thirteen".