1966 has 4 divisors (see below), whose sum is σ = 2952. Its totient is φ = 982.

The previous prime is 1951. The next prime is 1973. The reversal of 1966 is 6691.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a plaindrome in base 12 and base 16.

It is a nialpdrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490 + ... + 493.

It is an arithmetic number, because the mean of its divisors is an integer number (738).

1966 is a deficient number, since it is larger than the sum of its proper divisors (986).

1966 is an equidigital number, since it uses as much as digits as its factorization.

1966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 985.

The product of its digits is 324, while the sum is 22.

The square root of 1966 is about 44.3395985548. The cubic root of 1966 is about 12.5274065333.

It can be divided in two parts, 196 and 6, that multiplied together give a triangular number (1176 = T₄₈).

The spelling of 1966 in words is "one thousand, nine hundred sixty-six".