18861726244 has 9 divisors (see below), whose sum is σ = 33008501617. Its totient is φ = 9430725784.

The previous prime is 18861726239. The next prime is 18861726263. The reversal of 18861726244 is 44262716881.

It is a happy number.

The square root of 18861726244 is 137338.

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., 18834268644 + 27457600 = 137238^2 + 5240^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 240342 + ... + 309010.

Almost surely, 2^18861726244 is an apocalyptic number.

18861726244 is the 137338-th square number.

It is an amenable number.

18861726244 is a deficient number, since it is larger than the sum of its proper divisors (14146775373).

18861726244 is an frugal number, since it uses more digits than its factorization.

18861726244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137342 (or 68671 counting only the distinct ones).

The product of its digits is 1032192, while the sum is 49.

Multiplying 18861726244 by its sum of digits (49), we get a square (924224585956 = 961366²).

The spelling of 18861726244 in words is "eighteen billion, eight hundred sixty-one million, seven hundred twenty-six thousand, two hundred forty-four".