491987769 has 64 divisors (see below), whose sum is σ = 860461056. Its totient is φ = 242648064.

The previous prime is 491987759. The next prime is 491987777. The reversal of 491987769 is 967789194.

It is not a de Polignac number, because 491987769 - 2⁸ = 491987513 is a prime.

It is a super-2 number, since 2×491987769² = 484103929691194722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (491987759) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1053274 + ... + 1053740.

It is an arithmetic number, because the mean of its divisors is an integer number (13444704).

Almost surely, 2^491987769 is an apocalyptic number.

It is an amenable number.

491987769 is a deficient number, since it is larger than the sum of its proper divisors (368473287).

491987769 is a wasteful number, since it uses less digits than its factorization.

491987769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734.

The product of its digits is 6858432, while the sum is 60.

The square root of 491987769 is about 22180.7973030728. The cubic root of 491987769 is about 789.4381354419.

The spelling of 491987769 in words is "four hundred ninety-one million, nine hundred eighty-seven thousand, seven hundred sixty-nine".