491673961 has 8 divisors (see below), whose sum is σ = 497162664. Its totient is φ = 486205440.

The previous prime is 491673953. The next prime is 491673971. The reversal of 491673961 is 169376194.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 28090000 + 463583961 = 5300^2 + 21531^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 491673961 - 2³ = 491673953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491673971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46881 + ... + 56401.

It is an arithmetic number, because the mean of its divisors is an integer number (62145333).

Almost surely, 2^491673961 is an apocalyptic number.

It is an amenable number.

491673961 is a deficient number, since it is larger than the sum of its proper divisors (5488703).

491673961 is a wasteful number, since it uses less digits than its factorization.

491673961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10091.

The product of its digits is 244944, while the sum is 46.

The square root of 491673961 is about 22173.7223081737. The cubic root of 491673961 is about 789.2702554609.

The spelling of 491673961 in words is "four hundred ninety-one million, six hundred seventy-three thousand, nine hundred sixty-one".