1091383561 has 8 divisors (see below), whose sum is σ = 1186815240. Its totient is φ = 999422208.

The previous prime is 1091383549. The next prime is 1091383591. The reversal of 1091383561 is 1653831901.

It can be written as a sum of positive squares in 4 ways, for example, as 757955961 + 333427600 = 27531^2 + 18260^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1091383561 - 2²³ = 1082994953 is a prime.

It is a super-2 number, since 2×1091383561² = 2382236154442081442, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1091383561.

It is not an unprimeable number, because it can be changed into a prime (1091383591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 866926 + ... + 868183.

It is an arithmetic number, because the mean of its divisors is an integer number (148351905).

Almost surely, 2^1091383561 is an apocalyptic number.

It is an amenable number.

1091383561 is a deficient number, since it is larger than the sum of its proper divisors (95431679).

1091383561 is a wasteful number, since it uses less digits than its factorization.

1091383561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1735163.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 1091383561 is about 33036.0948206655. The cubic root of 1091383561 is about 1029.5777201954.

The spelling of 1091383561 in words is "one billion, ninety-one million, three hundred eighty-three thousand, five hundred sixty-one".