10989538561 has 3 divisors (see below), whose sum is σ = 10989643393. Its totient is φ = 10989433730.

The previous prime is 10989538481. The next prime is 10989538579. The reversal of 10989538561 is 16583598901.

The square root of 10989538561 is 104831.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 10989538561 - 2¹¹ = 10989536513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10989538591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 52416 + ... + 157246.

Almost surely, 2^10989538561 is an apocalyptic number.

10989538561 is the 104831-st square number.

10989538561 is the 52416-th centered octagonal number.

It is an amenable number.

10989538561 is a deficient number, since it is larger than the sum of its proper divisors (104832).

10989538561 is an frugal number, since it uses more digits than its factorization.

10989538561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209662 (or 104831 counting only the distinct ones).

The product of its (nonzero) digits is 2332800, while the sum is 55.

The spelling of 10989538561 in words is "ten billion, nine hundred eighty-nine million, five hundred thirty-eight thousand, five hundred sixty-one".