11561861 has 4 divisors (see below), whose sum is σ = 12170400. Its totient is φ = 10953324.

The previous prime is 11561843. The next prime is 11561863. The reversal of 11561861 is 16816511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16816511 = 197 ⋅85363.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11561861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11561863) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 304241 + ... + 304278.

It is an arithmetic number, because the mean of its divisors is an integer number (3042600).

Almost surely, 2^11561861 is an apocalyptic number.

It is an amenable number.

11561861 is a deficient number, since it is larger than the sum of its proper divisors (608539).

11561861 is an equidigital number, since it uses as much as digits as its factorization.

11561861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608538.

The product of its digits is 1440, while the sum is 29.

The square root of 11561861 is about 3400.2736654569. The cubic root of 11561861 is about 226.1218767276.

The spelling of 11561861 in words is "eleven million, five hundred sixty-one thousand, eight hundred sixty-one".