1971861 has 8 divisors (see below), whose sum is σ = 2638944. Its totient is φ = 1309680.

The previous prime is 1971857. The next prime is 1971869. The reversal of 1971861 is 1681791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1971861 - 2² = 1971857 is a prime.

It is a congruent number.

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, 150 + ... + 1991.

It is an arithmetic number, because the mean of its divisors is an integer number (329868).

2^1971861 is an apocalyptic number.

It is an amenable number.

1971861 is a deficient number, since it is larger than the sum of its proper divisors (667083).

1971861 is a wasteful number, since it uses less digits than its factorization.

1971861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2451.

The product of its digits is 3024, while the sum is 33.

The square root of 1971861 is about 1404.2296820677. The cubic root of 1971861 is about 125.3984300122.

The spelling of 1971861 in words is "one million, nine hundred seventy-one thousand, eight hundred sixty-one".