3561 has 4 divisors (see below), whose sum is σ = 4752.
Its totient is φ = 2372.
The previous prime is 3559. The next prime is 3571. The reversal of 3561 is 1653.
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 3561 - 21 = 3559 is a prime.
It is a D-number.
It is a self number, because there is not a number n which added to its sum of digits gives 3561.
It is not an unprimeable number, because it can be changed into a prime (3511) 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, 591 + ... + 596.
It is an arithmetic number, because the mean of its divisors is an integer number (1188).
It is an amenable number.
3561 is a deficient number, since it is larger than the sum of its proper divisors (1191).
3561 is a wasteful number, since it uses less digits than its factorization.
3561 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1190.
The product of its digits is 90, while the sum is 15.
The square root of 3561 is about 59.6741149913.
The cubic root of 3561 is about 15.2706430108.
The spelling of 3561 in words is "three thousand, five hundred sixty-one".