1685431579649 has 8 divisors (see below), whose sum is σ = 1784707824168. Its totient is φ = 1586170136320.

The previous prime is 1685431579633. The next prime is 1685431579661. The reversal of 1685431579649 is 9469751345861.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1382816068624 + 302615511025 = 1175932^2 + 550105^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1685431579649 - 2⁴ = 1685431579633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1685431579609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3465422 + ... + 3921735.

It is an arithmetic number, because the mean of its divisors is an integer number (223088478021).

Almost surely, 2^{1685431579649} is an apocalyptic number.

It is an amenable number.

1685431579649 is a deficient number, since it is larger than the sum of its proper divisors (99276244519).

1685431579649 is a wasteful number, since it uses less digits than its factorization.

1685431579649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7400595.

The product of its digits is 195955200, while the sum is 68.

The spelling of 1685431579649 in words is "one trillion, six hundred eighty-five billion, four hundred thirty-one million, five hundred seventy-nine thousand, six hundred forty-nine".