20008999 has 2 divisors, whose sum is σ = 20009000. Its totient is φ = 20008998.

The previous prime is 20008991. The next prime is 20009029. The reversal of 20008999 is 99980002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20008999 - 2³ = 20008991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20008991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10004499 + 10004500.

It is an arithmetic number, because the mean of its divisors is an integer number (10004500).

Almost surely, 2^20008999 is an apocalyptic number.

20008999 is a deficient number, since it is larger than the sum of its proper divisors (1).

20008999 is an equidigital number, since it uses as much as digits as its factorization.

20008999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 20008999 is about 4473.1419606357. The cubic root of 20008999 is about 271.4824672952.

The spelling of 20008999 in words is "twenty million, eight thousand, nine hundred ninety-nine".