9999385381 has 4 divisors (see below), whose sum is σ = 10066495500. Its totient is φ = 9932275264.

The previous prime is 9999385367. The next prime is 9999385387. The reversal of 9999385381 is 1835839999.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4133204100 + 5866181281 = 64290^2 + 76591^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999385381 - 2⁵ = 9999385349 is a prime.

It is a super-2 number, since 2×9999385381² (a number of 21 digits) 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 (9999385387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33554836 + ... + 33555133.

It is an arithmetic number, because the mean of its divisors is an integer number (2516623875).

Almost surely, 2^9999385381 is an apocalyptic number.

It is an amenable number.

9999385381 is a deficient number, since it is larger than the sum of its proper divisors (67110119).

9999385381 is a wasteful number, since it uses less digits than its factorization.

9999385381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67110118.

The product of its digits is 18895680, while the sum is 64.

The square root of 9999385381 is about 99996.9268577790. The cubic root of 9999385381 is about 2154.3905505777.

The spelling of 9999385381 in words is "nine billion, nine hundred ninety-nine million, three hundred eighty-five thousand, three hundred eighty-one".