1957891 has 4 divisors (see below), whose sum is σ = 2108512. Its totient is φ = 1807272.

The previous prime is 1957871. The next prime is 1957903. The reversal of 1957891 is 1987591.

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 1957891 - 2⁵ = 1957859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1957801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75291 + ... + 75316.

It is an arithmetic number, because the mean of its divisors is an integer number (527128).

2^1957891 is an apocalyptic number.

1957891 is a deficient number, since it is larger than the sum of its proper divisors (150621).

1957891 is a wasteful number, since it uses less digits than its factorization.

1957891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150620.

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

The square root of 1957891 is about 1399.2465829867. The cubic root of 1957891 is about 125.1015920767.

The spelling of 1957891 in words is "one million, nine hundred fifty-seven thousand, eight hundred ninety-one".