8181641520 has 600 divisors, whose sum is σ = 31894422912. Its totient is φ = 1940889600.

The previous prime is 8181641497. The next prime is 8181641591. The reversal of 8181641520 is 251461818.

8181641520 is a `hidden beast` number, since 8 + 1 + 8 + 1 + 641 + 5 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 33948600 + ... + 33948840.

Almost surely, 2^8181641520 is an apocalyptic number.

8181641520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8181641520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15947211456).

8181641520 is an abundant number, since it is smaller than the sum of its proper divisors (23712781392).

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

8181641520 is a wasteful number, since it uses less digits than its factorization.

8181641520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 295 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 8181641520 is about 90452.4268331149. The cubic root of 8181641520 is about 2015.0236556363.

The spelling of 8181641520 in words is "eight billion, one hundred eighty-one million, six hundred forty-one thousand, five hundred twenty".