491089985 has 16 divisors (see below), whose sum is σ = 597255120. Its totient is φ = 387594240.

The previous prime is 491089961. The next prime is 491089987. The reversal of 491089985 is 589980194.

It can be written as a sum of positive squares in 8 ways, for example, as 136445761 + 354644224 = 11681^2 + 18832^2 .

It is not a de Polignac number, because 491089985 - 2²⁶ = 423981121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (491089987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 262955 + ... + 264815.

It is an arithmetic number, because the mean of its divisors is an integer number (37328445).

Almost surely, 2^491089985 is an apocalyptic number.

It is an amenable number.

491089985 is a deficient number, since it is larger than the sum of its proper divisors (106165135).

491089985 is a wasteful number, since it uses less digits than its factorization.

491089985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2548.

The product of its (nonzero) digits is 933120, while the sum is 53.

The square root of 491089985 is about 22160.5501962384. The cubic root of 491089985 is about 788.9576516322.

The spelling of 491089985 in words is "four hundred ninety-one million, eighty-nine thousand, nine hundred eighty-five".