7899 has 4 divisors (see below), whose sum is σ = 10536. Its totient is φ = 5264.

The previous prime is 7883. The next prime is 7901. The reversal of 7899 is 9987.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9987 = 3 ⋅3329.

It is a cyclic number.

It is not a de Polignac number, because 7899 - 2⁴ = 7883 is a prime.

It is a D-number.

7899 is a modest number, since divided by 99 gives 78 as remainder.

7899 is a lucky number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (7829) 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, 1314 + ... + 1319.

It is an arithmetic number, because the mean of its divisors is an integer number (2634).

2⁷⁸⁹⁹ is an apocalyptic number.

7899 is a deficient number, since it is larger than the sum of its proper divisors (2637).

7899 is a wasteful number, since it uses less digits than its factorization.

7899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2636.

The product of its digits is 4536, while the sum is 33.

The square root of 7899 is about 88.8763185556. The cubic root of 7899 is about 19.9154766265.

The spelling of 7899 in words is "seven thousand, eight hundred ninety-nine".