491538686 has 8 divisors (see below), whose sum is σ = 739433880. Its totient is φ = 245060728.

The previous prime is 491538647. The next prime is 491538701. The reversal of 491538686 is 686835194.

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

It is a super-2 number, since 2×491538686² = 483220559669213192, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353441 + ... + 354828.

It is an arithmetic number, because the mean of its divisors is an integer number (92429235).

Almost surely, 2^491538686 is an apocalyptic number.

491538686 is a deficient number, since it is larger than the sum of its proper divisors (247895194).

491538686 is a wasteful number, since it uses less digits than its factorization.

491538686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708618.

The product of its digits is 1244160, while the sum is 50.

The square root of 491538686 is about 22170.6717534675. The cubic root of 491538686 is about 789.1978644487.

The spelling of 491538686 in words is "four hundred ninety-one million, five hundred thirty-eight thousand, six hundred eighty-six".