1091861568 has 84 divisors (see below), whose sum is σ = 3576726400. Its totient is φ = 311959296.

The previous prime is 1091861549. The next prime is 1091861569. The reversal of 1091861568 is 8651681901.

1091861568 is a `hidden beast` number, since 1 + 0 + 9 + 1 + 86 + 1 + 568 = 666.

It is a tau number, because it is divible by the number of its divisors (84).

It is not an unprimeable number, because it can be changed into a prime (1091861569) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 131368 + ... + 139431.

Almost surely, 2^1091861568 is an apocalyptic number.

1091861568 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1091861568 is an abundant number, since it is smaller than the sum of its proper divisors (2484864832).

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

1091861568 is a wasteful number, since it uses less digits than its factorization.

1091861568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270824 (or 270811 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The square root of 1091861568 is about 33043.3286458855. The cubic root of 1091861568 is about 1029.7280106285.

The spelling of 1091861568 in words is "one billion, ninety-one million, eight hundred sixty-one thousand, five hundred sixty-eight".