7843994 has 4 divisors (see below), whose sum is σ = 11765994. Its totient is φ = 3921996.

The previous prime is 7843981. The next prime is 7843999. The reversal of 7843994 is 4993487.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4993487 = 709 ⋅7043.

It can be written as a sum of positive squares in only one way, i.e., 5697769 + 2146225 = 2387^2 + 1465^2 .

It is not an unprimeable number, because it can be changed into a prime (7843999) 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, 1960997 + ... + 1961000.

Almost surely, 2^7843994 is an apocalyptic number.

7843994 is a deficient number, since it is larger than the sum of its proper divisors (3922000).

7843994 is a wasteful number, since it uses less digits than its factorization.

7843994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3921999.

The product of its digits is 217728, while the sum is 44.

The square root of 7843994 is about 2800.7131234741. The cubic root of 7843994 is about 198.6914065902.

The spelling of 7843994 in words is "seven million, eight hundred forty-three thousand, nine hundred ninety-four".