181209844868 has 24 divisors (see below), whose sum is σ = 341845448280. Its totient is φ = 83553373440.

The previous prime is 181209844763. The next prime is 181209844873. The reversal of 181209844868 is 868448902181.

It can be written as a sum of positive squares in 4 ways, for example, as 4735917124 + 176473927744 = 68818^2 + 420088^2 .

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, 1653473 + ... + 1759656.

It is an arithmetic number, because the mean of its divisors is an integer number (14243560345).

Almost surely, 2^181209844868 is an apocalyptic number.

It is an amenable number.

181209844868 is a deficient number, since it is larger than the sum of its proper divisors (160635603412).

181209844868 is a wasteful number, since it uses less digits than its factorization.

181209844868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3414167 (or 3414165 counting only the distinct ones).

The product of its (nonzero) digits is 7077888, while the sum is 59.

The spelling of 181209844868 in words is "one hundred eighty-one billion, two hundred nine million, eight hundred forty-four thousand, eight hundred sixty-eight".