491242261 has 4 divisors (see below), whose sum is σ = 501694272. Its totient is φ = 480790252.

The previous prime is 491242249. The next prime is 491242289. The reversal of 491242261 is 162242194.

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 a de Polignac number, because none of the positive numbers 2^k-491242261 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 (491243261) 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, 5225935 + ... + 5226028.

It is an arithmetic number, because the mean of its divisors is an integer number (125423568).

Almost surely, 2^491242261 is an apocalyptic number.

It is an amenable number.

491242261 is a deficient number, since it is larger than the sum of its proper divisors (10452011).

491242261 is a wasteful number, since it uses less digits than its factorization.

491242261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10452010.

The product of its digits is 6912, while the sum is 31.

The square root of 491242261 is about 22163.9856749638. The cubic root of 491242261 is about 789.0391892347.

The spelling of 491242261 in words is "four hundred ninety-one million, two hundred forty-two thousand, two hundred sixty-one".