1091571517089 has 45 divisors (see below), whose sum is σ = 1689208318083. Its totient is φ = 702445223088.

The previous prime is 1091571517087. The next prime is 1091571517093. The reversal of 1091571517089 is 9807151751901.

The square root of 1091571517089 is 1044783.

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

1091571517089 is a `hidden beast` number, since 10 + 9 + 1 + 571 + 51 + 7 + 0 + 8 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 572393625489 + 519177891600 = 756567^2 + 720540^2 .

It is not a de Polignac number, because 1091571517089 - 2¹ = 1091571517087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1091571517081) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 272686362 + ... + 272690364.

Almost surely, 2^{1091571517089} is an apocalyptic number.

1091571517089 is the 1044783-rd square number.

1091571517089 is the 522392-nd centered octagonal number.

It is an amenable number.

1091571517089 is a deficient number, since it is larger than the sum of its proper divisors (597636800994).

1091571517089 is an frugal number, since it uses more digits than its factorization.

1091571517089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8076 (or 4035 counting only the distinct ones).

The product of its (nonzero) digits is 793800, while the sum is 54.

The spelling of 1091571517089 in words is "one trillion, ninety-one billion, five hundred seventy-one million, five hundred seventeen thousand, eighty-nine".