2157943 has 4 divisors (see below), whose sum is σ = 2160928. Its totient is φ = 2154960.

The previous prime is 2157923. The next prime is 2157989. The reversal of 2157943 is 3497512.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2157943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157913) 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 in 3 ways as a sum of consecutive naturals, for example, 355 + ... + 2107.

It is an arithmetic number, because the mean of its divisors is an integer number (540232).

2^2157943 is an apocalyptic number.

2157943 is a deficient number, since it is larger than the sum of its proper divisors (2985).

2157943 is a wasteful number, since it uses less digits than its factorization.

2157943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2984.

The product of its digits is 7560, while the sum is 31.

The square root of 2157943 is about 1468.9938733705. The cubic root of 2157943 is about 129.2250343678.

The spelling of 2157943 in words is "two million, one hundred fifty-seven thousand, nine hundred forty-three".