491956961 has 4 divisors (see below), whose sum is σ = 496827924. Its totient is φ = 487086000.

The previous prime is 491956939. The next prime is 491957029. The reversal of 491956961 is 169659194.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 482065936 + 9891025 = 21956^2 + 3145^2 .

It is a cyclic number.

It is not a de Polignac number, because 491956961 - 2¹⁸ = 491694817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491956901) 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, 2435330 + ... + 2435531.

It is an arithmetic number, because the mean of its divisors is an integer number (124206981).

Almost surely, 2^491956961 is an apocalyptic number.

It is an amenable number.

491956961 is a deficient number, since it is larger than the sum of its proper divisors (4870963).

491956961 is a wasteful number, since it uses less digits than its factorization.

491956961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4870962.

The product of its digits is 524880, while the sum is 50.

The square root of 491956961 is about 22180.1028176156. The cubic root of 491956961 is about 789.4216570392.

The spelling of 491956961 in words is "four hundred ninety-one million, nine hundred fifty-six thousand, nine hundred sixty-one".