1971866 has 16 divisors (see below), whose sum is σ = 3213000. Its totient is φ = 902208.

The previous prime is 1971857. The next prime is 1971869. The reversal of 1971866 is 6681791.

It can be written as a sum of positive squares in 4 ways, for example, as 1274641 + 697225 = 1129^2 + 835^2 .

It is not an unprimeable number, because it can be changed into a prime (1971869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3620 + ... + 4128.

2^1971866 is an apocalyptic number.

1971866 is a deficient number, since it is larger than the sum of its proper divisors (1241134).

1971866 is a wasteful number, since it uses less digits than its factorization.

1971866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673.

The product of its digits is 18144, while the sum is 38.

The square root of 1971866 is about 1404.2314624021. The cubic root of 1971866 is about 125.3985360020.

The spelling of 1971866 in words is "one million, nine hundred seventy-one thousand, eight hundred sixty-six".