1971887 has 2 divisors, whose sum is σ = 1971888. Its totient is φ = 1971886.

The previous prime is 1971869. The next prime is 1971889. The reversal of 1971887 is 7881791.

It is a strong prime.

It is an emirp because it is prime and its reverse (7881791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1971887 - 2²⁰ = 923311 is a prime.

Together with 1971889, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1971889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985943 + 985944.

It is an arithmetic number, because the mean of its divisors is an integer number (985944).

2^1971887 is an apocalyptic number.

1971887 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971887 is an equidigital number, since it uses as much as digits as its factorization.

1971887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 41.

The square root of 1971887 is about 1404.2389397820. The cubic root of 1971887 is about 125.3989811574.

The spelling of 1971887 in words is "one million, nine hundred seventy-one thousand, eight hundred eighty-seven".