2099639 has 4 divisors (see below), whose sum is σ = 2156424. Its totient is φ = 2042856.

The previous prime is 2099627. The next prime is 2099641. The reversal of 2099639 is 9369902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9369902 = 2 ⋅4684951.

It is a cyclic number.

It is not a de Polignac number, because 2099639 - 2⁴ = 2099623 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 (2099659) 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, 28337 + ... + 28410.

It is an arithmetic number, because the mean of its divisors is an integer number (539106).

2^2099639 is an apocalyptic number.

2099639 is a deficient number, since it is larger than the sum of its proper divisors (56785).

2099639 is an equidigital number, since it uses as much as digits as its factorization.

2099639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56784.

The product of its (nonzero) digits is 26244, while the sum is 38.

The square root of 2099639 is about 1449.0131124320. The cubic root of 2099639 is about 128.0505781564.

Subtracting from 2099639 its sum of digits (38), we obtain a square (2099601 = 1449²).

The spelling of 2099639 in words is "two million, ninety-nine thousand, six hundred thirty-nine".