1566 has 16 divisors (see below), whose sum is σ = 3600. Its totient is φ = 504.

The previous prime is 1559. The next prime is 1567. The reversal of 1566 is 6651.

1566 is nontrivially palindromic in base 15.

It is a Harshad number since it is a multiple of its sum of digits (18).

1566 is an undulating number in base 15.

It is a plaindrome in base 10.

It is a nialpdrome in base 12.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 1566.

It is not an unprimeable number, because it can be changed into a prime (1567) by changing a digit.

1566 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40 + ... + 68.

It is an arithmetic number, because the mean of its divisors is an integer number (225).

It is a practical number, because each smaller number is the sum of distinct divisors of 1566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1800).

1566 is an abundant number, since it is smaller than the sum of its proper divisors (2034).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1566 is a wasteful number, since it uses less digits than its factorization.

1566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40 (or 34 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 1566 is about 39.5727178748. The cubic root of 1566 is about 11.6126299219.

It can be divided in two parts, 15 and 66, that multiplied together give a triangular number (990 = T₄₄).

The spelling of 1566 in words is "one thousand, five hundred sixty-six".