1985305381 has 8 divisors (see below), whose sum is σ = 1996454880. Its totient is φ = 1974187248.

The previous prime is 1985305367. The next prime is 1985305397. The reversal of 1985305381 is 1835035891.

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 1985305381 - 2¹⁵ = 1985272613 is a prime.

It is a super-2 number, since 2×1985305381² = 7882874911655110322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1985305351) 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, 125350 + ... + 140296.

It is an arithmetic number, because the mean of its divisors is an integer number (249556860).

Almost surely, 2^1985305381 is an apocalyptic number.

It is an amenable number.

1985305381 is a deficient number, since it is larger than the sum of its proper divisors (11149499).

1985305381 is a wasteful number, since it uses less digits than its factorization.

1985305381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15683.

The product of its (nonzero) digits is 129600, while the sum is 43.

The square root of 1985305381 is about 44556.7658274251. The cubic root of 1985305381 is about 1256.8277851225.

The spelling of 1985305381 in words is "one billion, nine hundred eighty-five million, three hundred five thousand, three hundred eighty-one".