1691665449 has 8 divisors (see below), whose sum is σ = 2268592512. Its totient is φ = 1121257680.

The previous prime is 1691665447. The next prime is 1691665541. The reversal of 1691665449 is 9445661961.

It is a happy number.

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

It is not a de Polignac number, because 1691665449 - 2¹ = 1691665447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1691665441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1629217 + ... + 1630254.

It is an arithmetic number, because the mean of its divisors is an integer number (283574064).

Almost surely, 2^1691665449 is an apocalyptic number.

It is an amenable number.

1691665449 is a deficient number, since it is larger than the sum of its proper divisors (576927063).

1691665449 is a wasteful number, since it uses less digits than its factorization.

1691665449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3259647.

The product of its digits is 1399680, while the sum is 51.

The square root of 1691665449 is about 41129.8607948045. The cubic root of 1691665449 is about 1191.5295749009.

The spelling of 1691665449 in words is "one billion, six hundred ninety-one million, six hundred sixty-five thousand, four hundred forty-nine".