1631668491 has 18 divisors (see below), whose sum is σ = 2481702860. Its totient is φ = 1030193856.

The previous prime is 1631668463. The next prime is 1631668589. The reversal of 1631668491 is 1948661361.

1631668491 is a `hidden beast` number, since 1 + 631 + 6 + 6 + 8 + 4 + 9 + 1 = 666.

It is not a de Polignac number, because 1631668491 - 2¹⁴ = 1631652107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1631668091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 526675 + ... + 529763.

Almost surely, 2^1631668491 is an apocalyptic number.

1631668491 is a deficient number, since it is larger than the sum of its proper divisors (850034369).

1631668491 is an frugal number, since it uses more digits than its factorization.

1631668491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6203 (or 3111 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 1631668491 is about 40393.9165097914. The cubic root of 1631668491 is about 1177.2733392004.

The spelling of 1631668491 in words is "one billion, six hundred thirty-one million, six hundred sixty-eight thousand, four hundred ninety-one".