1091118564 has 18 divisors (see below), whose sum is σ = 2758105350. Its totient is φ = 363706176.

The previous prime is 1091118547. The next prime is 1091118571. The reversal of 1091118564 is 4658111901.

It is a happy number.

1091118564 is a `hidden beast` number, since 1 + 0 + 91 + 1 + 1 + 8 + 564 = 666.

It can be written as a sum of positive squares in only one way, i.e., 735494400 + 355624164 = 27120^2 + 18858^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 30308849 = 1091118564 / (1 + 0 + 9 + 1 + 1 + 1 + 8 + 5 + 6 + 4).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15154389 + ... + 15154460.

It is an arithmetic number, because the mean of its divisors is an integer number (153228075).

Almost surely, 2^1091118564 is an apocalyptic number.

It is an amenable number.

1091118564 is an abundant number, since it is smaller than the sum of its proper divisors (1666986786).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1091118564 is a wasteful number, since it uses less digits than its factorization.

1091118564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30308859 (or 30308854 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 36.

The square root of 1091118564 is about 33032.0838579706. The cubic root of 1091118564 is about 1029.4943834407.

The spelling of 1091118564 in words is "one billion, ninety-one million, one hundred eighteen thousand, five hundred sixty-four".