491223839 has 4 divisors (see below), whose sum is σ = 495814824. Its totient is φ = 486632856.

The previous prime is 491223827. The next prime is 491223847. The reversal of 491223839 is 938322194.

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-491223839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 491223796 and 491223805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491223539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2295332 + ... + 2295545.

It is an arithmetic number, because the mean of its divisors is an integer number (123953706).

Almost surely, 2^491223839 is an apocalyptic number.

491223839 is a deficient number, since it is larger than the sum of its proper divisors (4590985).

491223839 is a wasteful number, since it uses less digits than its factorization.

491223839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4590984.

The product of its digits is 93312, while the sum is 41.

The square root of 491223839 is about 22163.5700869693. The cubic root of 491223839 is about 789.0293258992.

The spelling of 491223839 in words is "four hundred ninety-one million, two hundred twenty-three thousand, eight hundred thirty-nine".