1971 has 8 divisors (see below), whose sum is σ = 2960. Its totient is φ = 1296.

The previous prime is 1951. The next prime is 1973. The reversal of 1971 is 1791.

1971 is nontrivially palindromic in base 8.

It is not a de Polignac number, because 1971 - 2⁶ = 1907 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

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 1971.

It is not an unprimeable number, because it can be changed into a prime (1973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10 + ... + 63.

It is an arithmetic number, because the mean of its divisors is an integer number (370).

1971 is a deficient number, since it is larger than the sum of its proper divisors (989).

1971 is an equidigital number, since it uses as much as digits as its factorization.

1971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82 (or 76 counting only the distinct ones).

The product of its digits is 63, while the sum is 18.

The square root of 1971 is about 44.3959457608. The cubic root of 1971 is about 12.5380175891.

Subtracting from 1971 its sum of digits (18), we obtain a triangular number (1953 = T₆₂).

The spelling of 1971 in words is "one thousand, nine hundred seventy-one".