11561643 has 16 divisors (see below), whose sum is σ = 17184160. Its totient is φ = 7682688.

The previous prime is 11561639. The next prime is 11561653. The reversal of 11561643 is 34616511.

11561643 is a `hidden beast` number, since 1 + 1 + 5 + 616 + 43 = 666.

11561643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11561643 - 2² = 11561639 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11561653) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11871 + ... + 12807.

It is an arithmetic number, because the mean of its divisors is an integer number (1074010).

Almost surely, 2^11561643 is an apocalyptic number.

11561643 is a deficient number, since it is larger than the sum of its proper divisors (5622517).

11561643 is an equidigital number, since it uses as much as digits as its factorization.

11561643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1403 (or 1397 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 11561643 is about 3400.2416090625. The cubic root of 11561643 is about 226.1204555355.

The spelling of 11561643 in words is "eleven million, five hundred sixty-one thousand, six hundred forty-three".