10865561 has 4 divisors (see below), whose sum is σ = 12417792. Its totient is φ = 9313332.

The previous prime is 10865557. The next prime is 10865609. The reversal of 10865561 is 16556801.

It is a happy number.

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: 16556801 = 281 ⋅58921.

It is not a de Polignac number, because 10865561 - 2² = 10865557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (10865761) 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 3 ways as a sum of consecutive naturals, for example, 776105 + ... + 776118.

It is an arithmetic number, because the mean of its divisors is an integer number (3104448).

Almost surely, 2^10865561 is an apocalyptic number.

It is an amenable number.

10865561 is a deficient number, since it is larger than the sum of its proper divisors (1552231).

10865561 is an equidigital number, since it uses as much as digits as its factorization.

10865561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1552230.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 10865561 is about 3296.2950414063. The cubic root of 10865561 is about 221.4882634372.

The spelling of 10865561 in words is "ten million, eight hundred sixty-five thousand, five hundred sixty-one".