181252844644 has 9 divisors (see below), whose sum is σ = 317193968217. Its totient is φ = 90625996584.

The previous prime is 181252844609. The next prime is 181252844651. The reversal of 181252844644 is 446448252181.

It is a happy number.

The square root of 181252844644 is 425738.

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

It can be written as a sum of positive squares in only one way, i.e., 116716523044 + 64536321600 = 341638^2 + 254040^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 745042 + ... + 957910.

Almost surely, 2^181252844644 is an apocalyptic number.

181252844644 is the 425738-th square number.

It is an amenable number.

181252844644 is a deficient number, since it is larger than the sum of its proper divisors (135941123573).

181252844644 is an frugal number, since it uses more digits than its factorization.

181252844644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425742 (or 212871 counting only the distinct ones).

The product of its digits is 1966080, while the sum is 49.

Multiplying 181252844644 by its sum of digits (49), we get a square (8881389387556 = 2980166²).

The spelling of 181252844644 in words is "one hundred eighty-one billion, two hundred fifty-two million, eight hundred forty-four thousand, six hundred forty-four".