1975891 has 4 divisors (see below), whose sum is σ = 2003032. Its totient is φ = 1948752.

The previous prime is 1975823. The next prime is 1975901. The reversal of 1975891 is 1985791.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1975891 - 2¹⁷ = 1844819 is a prime.

It is a Duffinian number.

1975891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1975811) 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 3 ways as a sum of consecutive naturals, for example, 13461 + ... + 13606.

It is an arithmetic number, because the mean of its divisors is an integer number (500758).

2^1975891 is an apocalyptic number.

1975891 is a deficient number, since it is larger than the sum of its proper divisors (27141).

1975891 is an equidigital number, since it uses as much as digits as its factorization.

1975891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27140.

The product of its digits is 22680, while the sum is 40.

The square root of 1975891 is about 1405.6639000842. The cubic root of 1975891 is about 125.4837997533.

The spelling of 1975891 in words is "one million, nine hundred seventy-five thousand, eight hundred ninety-one".