491879657 has 4 divisors (see below), whose sum is σ = 517768080. Its totient is φ = 465991236.

The previous prime is 491879651. The next prime is 491879659. The reversal of 491879657 is 756978194.

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 not a de Polignac number, because 491879657 - 2¹² = 491875561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491879651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12944183 + ... + 12944220.

It is an arithmetic number, because the mean of its divisors is an integer number (129442020).

Almost surely, 2^491879657 is an apocalyptic number.

It is an amenable number.

491879657 is a deficient number, since it is larger than the sum of its proper divisors (25888423).

491879657 is a wasteful number, since it uses less digits than its factorization.

491879657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25888422.

The product of its digits is 3810240, while the sum is 56.

The square root of 491879657 is about 22178.3601061936. The cubic root of 491879657 is about 789.3803060991.

The spelling of 491879657 in words is "four hundred ninety-one million, eight hundred seventy-nine thousand, six hundred fifty-seven".