491999545 has 16 divisors (see below), whose sum is σ = 607892688. Its totient is φ = 381991680.

The previous prime is 491999539. The next prime is 491999561. The reversal of 491999545 is 545999194.

It can be written as a sum of positive squares in 8 ways, for example, as 16192576 + 475806969 = 4024^2 + 21813^2 .

It is not a de Polignac number, because 491999545 - 2³ = 491999537 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74727 + ... + 81043.

It is an arithmetic number, because the mean of its divisors is an integer number (37993293).

Almost surely, 2^491999545 is an apocalyptic number.

It is an amenable number.

491999545 is a deficient number, since it is larger than the sum of its proper divisors (115893143).

491999545 is a wasteful number, since it uses less digits than its factorization.

491999545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6780.

The product of its digits is 2624400, while the sum is 55.

The square root of 491999545 is about 22181.0627563244. The cubic root of 491999545 is about 789.4444339381. Note that the first 4 decimals are identical.

The spelling of 491999545 in words is "four hundred ninety-one million, nine hundred ninety-nine thousand, five hundred forty-five".