80999 has 4 divisors (see below), whose sum is σ = 81864. Its totient is φ = 80136.

The previous prime is 80989. The next prime is 81001. The reversal of 80999 is 99908.

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-80999 is a prime.

It is a Duffinian number.

80999 is a modest number, since divided by 999 gives 80 as remainder.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80909) 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, 272 + ... + 485.

It is an arithmetic number, because the mean of its divisors is an integer number (20466).

2⁸⁰⁹⁹⁹ is an apocalyptic number.

80999 is a deficient number, since it is larger than the sum of its proper divisors (865).

80999 is a wasteful number, since it uses less digits than its factorization.

80999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 864.

The product of its (nonzero) digits is 5832, while the sum is 35.

The square root of 80999 is about 284.6032325888. The cubic root of 80999 is about 43.2673090530.

The spelling of 80999 in words is "eighty thousand, nine hundred ninety-nine".