100999 has 2 divisors, whose sum is σ = 101000. Its totient is φ = 100998.

The previous prime is 100987. The next prime is 101009. The reversal of 100999 is 999001.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100999 is a prime.

100999 is a modest number, since divided by 999 gives 100 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50499 + 50500.

It is an arithmetic number, because the mean of its divisors is an integer number (50500).

2¹⁰⁰⁹⁹⁹ is an apocalyptic number.

100999 is a deficient number, since it is larger than the sum of its proper divisors (1).

100999 is an equidigital number, since it uses as much as digits as its factorization.

100999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 28.

The square root of 100999 is about 317.8033983456. The cubic root of 100999 is about 46.5699413808.

The spelling of 100999 in words is "one hundred thousand, nine hundred ninety-nine".