123198894009 has 27 divisors (see below), whose sum is σ = 180356833839. Its totient is φ = 81038187360.

The previous prime is 123198893989. The next prime is 123198894011. The reversal of 123198894009 is 900498891321.

The square root of 123198894009 is 350997.

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., 52740500409 + 70458393600 = 229653^2 + 265440^2 .

It is not a de Polignac number, because 123198894009 - 2⁵ = 123198893977 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (123198894089) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 83185549 + ... + 83187029.

Almost surely, 2^123198894009 is an apocalyptic number.

123198894009 is the 350997-th square number.

123198894009 is the 175499-th centered octagonal number.

It is an amenable number.

123198894009 is a deficient number, since it is larger than the sum of its proper divisors (57157939830).

123198894009 is an frugal number, since it uses more digits than its factorization.

123198894009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3126 (or 1563 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 123198894009 in words is "one hundred twenty-three billion, one hundred ninety-eight million, eight hundred ninety-four thousand, nine".