7856749 has 4 divisors (see below), whose sum is σ = 7862364. Its totient is φ = 7851136.

The previous prime is 7856743. The next prime is 7856759. The reversal of 7856749 is 9476587.

It is a happy number.

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 can be written as a sum of positive squares in 2 ways, for example, as 3204100 + 4652649 = 1790^2 + 2157^2 .

It is a cyclic number.

It is not a de Polignac number, because 7856749 - 2³ = 7856741 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7856699 and 7856708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7856741) 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, 1179 + ... + 4135.

It is an arithmetic number, because the mean of its divisors is an integer number (1965591).

Almost surely, 2^7856749 is an apocalyptic number.

It is an amenable number.

7856749 is a deficient number, since it is larger than the sum of its proper divisors (5615).

7856749 is a wasteful number, since it uses less digits than its factorization.

7856749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5614.

The product of its digits is 423360, while the sum is 46.

The square root of 7856749 is about 2802.9892971612. The cubic root of 7856749 is about 198.7990446321.

The spelling of 7856749 in words is "seven million, eight hundred fifty-six thousand, seven hundred forty-nine".