11645561 has 16 divisors (see below), whose sum is σ = 12830400. Its totient is φ = 10526208.

The previous prime is 11645551. The next prime is 11645563. The reversal of 11645561 is 16554611.

It is not a de Polignac number, because 11645561 - 2⁶ = 11645497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11645563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64970 + ... + 65148.

It is an arithmetic number, because the mean of its divisors is an integer number (801900).

Almost surely, 2^11645561 is an apocalyptic number.

It is an amenable number.

11645561 is a deficient number, since it is larger than the sum of its proper divisors (1184839).

11645561 is a wasteful number, since it uses less digits than its factorization.

11645561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328.

The product of its digits is 3600, while the sum is 29.

The square root of 11645561 is about 3412.5593035140. The cubic root of 11645561 is about 226.6662214044. Note that the first 3 decimals are identical.

The spelling of 11645561 in words is "eleven million, six hundred forty-five thousand, five hundred sixty-one".