491188213 has 2 divisors, whose sum is σ = 491188214. Its totient is φ = 491188212.

The previous prime is 491188199. The next prime is 491188219. The reversal of 491188213 is 312881194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 368908849 + 122279364 = 19207^2 + 11058^2 .

It is a cyclic number.

It is not a de Polignac number, because 491188213 - 2¹³ = 491180021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491188219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245594106 + 245594107.

It is an arithmetic number, because the mean of its divisors is an integer number (245594107).

Almost surely, 2^491188213 is an apocalyptic number.

It is an amenable number.

491188213 is a deficient number, since it is larger than the sum of its proper divisors (1).

491188213 is an equidigital number, since it uses as much as digits as its factorization.

491188213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 37.

The square root of 491188213 is about 22162.7663661376. The cubic root of 491188213 is about 789.0102506589.

It can be divided in two parts, 491188 and 213, that added together give a square (491401 = 701²).

The spelling of 491188213 in words is "four hundred ninety-one million, one hundred eighty-eight thousand, two hundred thirteen".