1985665129 has 8 divisors (see below), whose sum is σ = 2388770240. Its totient is φ = 1612419696.

The previous prime is 1985665117. The next prime is 1985665147. The reversal of 1985665129 is 9215665891.

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 1985665129 - 2²¹ = 1983567977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1985665159) 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, 7464774 + ... + 7465039.

It is an arithmetic number, because the mean of its divisors is an integer number (298596280).

Almost surely, 2^1985665129 is an apocalyptic number.

1985665129 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1985665129 is a deficient number, since it is larger than the sum of its proper divisors (403105111).

1985665129 is a wasteful number, since it uses less digits than its factorization.

1985665129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14929839.

The product of its digits is 1166400, while the sum is 52.

The square root of 1985665129 is about 44560.8026072242. The cubic root of 1985665129 is about 1256.9036951863.

The spelling of 1985665129 in words is "one billion, nine hundred eighty-five million, six hundred sixty-five thousand, one hundred twenty-nine".