9985155831 has 24 divisors (see below), whose sum is σ = 17015158784. Its totient is φ = 5521744080.

The previous prime is 9985155821. The next prime is 9985155833. The reversal of 9985155831 is 1385515899.

It is a happy number.

9985155831 is a `hidden beast` number, since 9 + 9 + 8 + 51 + 5 + 583 + 1 = 666.

It is not a de Polignac number, because 9985155831 - 2⁹ = 9985155319 is a prime.

It is a super-2 number, since 2×9985155831² (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 (9985155833) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2554411 + ... + 2558316.

Almost surely, 2^9985155831 is an apocalyptic number.

9985155831 is a deficient number, since it is larger than the sum of its proper divisors (7030002953).

9985155831 is a wasteful number, since it uses less digits than its factorization.

9985155831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5112771 (or 5112768 counting only the distinct ones).

The product of its digits is 1944000, while the sum is 54.

The square root of 9985155831 is about 99925.7515908687. The cubic root of 9985155831 is about 2153.3681356993.

The spelling of 9985155831 in words is "nine billion, nine hundred eighty-five million, one hundred fifty-five thousand, eight hundred thirty-one".