11287561 has 4 divisors (see below), whose sum is σ = 11350800. Its totient is φ = 11224324.

The previous prime is 11287559. The next prime is 11287579. The reversal of 11287561 is 16578211.

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.

It is a cyclic number.

It is not a de Polignac number, because 11287561 - 2¹ = 11287559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11287511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31351 + ... + 31708.

It is an arithmetic number, because the mean of its divisors is an integer number (2837700).

Almost surely, 2^11287561 is an apocalyptic number.

It is an amenable number.

11287561 is a deficient number, since it is larger than the sum of its proper divisors (63239).

11287561 is an equidigital number, since it uses as much as digits as its factorization.

11287561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63238.

The product of its digits is 3360, while the sum is 31.

The square root of 11287561 is about 3359.6965636795. The cubic root of 11287561 is about 224.3193322274.

The spelling of 11287561 in words is "eleven million, two hundred eighty-seven thousand, five hundred sixty-one".