808181222121 has 243 divisors, whose sum is σ = 1528446095631. Its totient is φ = 410111589888.

The previous prime is 808181222111. The next prime is 808181222153. The reversal of 808181222121 is 121222181808.

The square root of 808181222121 is 898989.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 609978182121 + 198203040000 = 781011^2 + 445200^2 .

It is not a de Polignac number, because 808181222121 - 2⁵ = 808181222089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (808181222111) by changing a digit.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 9080687845 + ... + 9080687933.

Almost surely, 2^808181222121 is an apocalyptic number.

808181222121 is the 898989-th square number.

808181222121 is the 449495-th centered octagonal number.

It is an amenable number.

808181222121 is a deficient number, since it is larger than the sum of its proper divisors (720264873510).

808181222121 is a wasteful number, since it uses less digits than its factorization.

808181222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 36.

Multiplying 808181222121 by its sum of digits (36), we get a square (29094523996356 = 5393934²).

The spelling of 808181222121 in words is "eight hundred eight billion, one hundred eighty-one million, two hundred twenty-two thousand, one hundred twenty-one".