7857994 has 4 divisors (see below), whose sum is σ = 11786994. Its totient is φ = 3928996.

The previous prime is 7857989. The next prime is 7858003. The reversal of 7857994 is 4997587.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4997587 = 7 ⋅713941.

It can be written as a sum of positive squares in only one way, i.e., 6827769 + 1030225 = 2613^2 + 1015^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1964497 + ... + 1964500.

Almost surely, 2^7857994 is an apocalyptic number.

7857994 is a deficient number, since it is larger than the sum of its proper divisors (3929000).

7857994 is a wasteful number, since it uses less digits than its factorization.

7857994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3928999.

The product of its digits is 635040, while the sum is 49.

The square root of 7857994 is about 2803.2113726938. The cubic root of 7857994 is about 198.8095448080.

The spelling of 7857994 in words is "seven million, eight hundred fifty-seven thousand, nine hundred ninety-four".