8181971508 has 24 divisors (see below), whose sum is σ = 19092844512. Its totient is φ = 2727098464.

The previous prime is 8181971471. The next prime is 8181971533. The reversal of 8181971508 is 8051791818.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191791 + ... + 230537.

It is an arithmetic number, because the mean of its divisors is an integer number (795535188).

Almost surely, 2^8181971508 is an apocalyptic number.

It is an amenable number.

8181971508 is an abundant number, since it is smaller than the sum of its proper divisors (10910873004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8181971508 is a wasteful number, since it uses less digits than its factorization.

8181971508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56351 (or 56349 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 48.

The square root of 8181971508 is about 90454.2509117178. The cubic root of 8181971508 is about 2015.0507457455.

The spelling of 8181971508 in words is "eight billion, one hundred eighty-one million, nine hundred seventy-one thousand, five hundred eight".