5815815381 has 24 divisors (see below), whose sum is σ = 8509877376. Its totient is φ = 3827031840.

The previous prime is 5815815371. The next prime is 5815815389. The reversal of 5815815381 is 1835185185.

5815815381 is a `hidden beast` number, since 581 + 58 + 15 + 3 + 8 + 1 = 666.

It is not a de Polignac number, because 5815815381 - 2⁷ = 5815815253 is a prime.

It is a super-3 number, since 3×5815815381³ (a number of 30 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5815815389) 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 23 ways as a sum of consecutive naturals, for example, 278211 + ... + 298383.

It is an arithmetic number, because the mean of its divisors is an integer number (354578224).

Almost surely, 2^5815815381 is an apocalyptic number.

It is an amenable number.

5815815381 is a deficient number, since it is larger than the sum of its proper divisors (2694061995).

5815815381 is a wasteful number, since it uses less digits than its factorization.

5815815381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20593 (or 20590 counting only the distinct ones).

The product of its digits is 192000, while the sum is 45.

The square root of 5815815381 is about 76261.4934354160. The cubic root of 5815815381 is about 1798.3333730807. Note that the first 4 decimals are identical.

The spelling of 5815815381 in words is "five billion, eight hundred fifteen million, eight hundred fifteen thousand, three hundred eighty-one".