8181210505 has 32 divisors (see below), whose sum is σ = 10825119648. Its totient is φ = 5898700800.

The previous prime is 8181210467. The next prime is 8181210553. The reversal of 8181210505 is 5050121818.

It can be written as a sum of positive squares in 16 ways, for example, as 3975428601 + 4205781904 = 63051^2 + 64852^2 .

It is not a de Polignac number, because 8181210505 - 2¹³ = 8181202313 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 535675 + ... + 550735.

It is an arithmetic number, because the mean of its divisors is an integer number (338284989).

Almost surely, 2^8181210505 is an apocalyptic number.

It is an amenable number.

8181210505 is a deficient number, since it is larger than the sum of its proper divisors (2643909143).

8181210505 is a wasteful number, since it uses less digits than its factorization.

8181210505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15277.

The product of its (nonzero) digits is 3200, while the sum is 31.

The square root of 8181210505 is about 90450.0442509566. The cubic root of 8181210505 is about 2014.9882706967.

The spelling of 8181210505 in words is "eight billion, one hundred eighty-one million, two hundred ten thousand, five hundred five".