1686129985 has 8 divisors (see below), whose sum is σ = 2033524800. Its totient is φ = 1342124784.

The previous prime is 1686129979. The next prime is 1686130003. The reversal of 1686129985 is 5899216861.

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 1686129985 - 2¹⁷ = 1685998913 is a prime.

It is a super-2 number, since 2×1686129985² = 5686068652632200450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 846307 + ... + 848296.

It is an arithmetic number, because the mean of its divisors is an integer number (254190600).

Almost surely, 2^1686129985 is an apocalyptic number.

It is an amenable number.

1686129985 is a deficient number, since it is larger than the sum of its proper divisors (347394815).

1686129985 is a wasteful number, since it uses less digits than its factorization.

1686129985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1694807.

The product of its digits is 1866240, while the sum is 55.

The square root of 1686129985 is about 41062.5131354621. The cubic root of 1686129985 is about 1190.2285145980.

The spelling of 1686129985 in words is "one billion, six hundred eighty-six million, one hundred twenty-nine thousand, nine hundred eighty-five".