10001999 has 16 divisors (see below), whose sum is σ = 12134400. Its totient is φ = 8053344.

The previous prime is 10001963. The next prime is 10002007. The reversal of 10001999 is 99910001.

It is a cyclic number.

It is not a de Polignac number, because 10001999 - 2²⁰ = 8953423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10001399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20642 + ... + 21120.

It is an arithmetic number, because the mean of its divisors is an integer number (758400).

Almost surely, 2^10001999 is an apocalyptic number.

10001999 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

10001999 is a deficient number, since it is larger than the sum of its proper divisors (2132401).

10001999 is a wasteful number, since it uses less digits than its factorization.

10001999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 10001999 is about 3162.5937140265. The cubic root of 10001999 is about 215.4578237632.

It can be divided in two parts, 10001 and 999, that multiplied together give a palindrome (9990999).

The spelling of 10001999 in words is "ten million, one thousand, nine hundred ninety-nine".