2129009 has 4 divisors (see below), whose sum is σ = 2136816. Its totient is φ = 2121204.

The previous prime is 2129003. The next prime is 2129011. The reversal of 2129009 is 9009212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2129009 - 2⁴ = 2128993 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2129003) 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, 3479 + ... + 4044.

It is an arithmetic number, because the mean of its divisors is an integer number (534204).

2^2129009 is an apocalyptic number.

It is an amenable number.

2129009 is a deficient number, since it is larger than the sum of its proper divisors (7807).

2129009 is an equidigital number, since it uses as much as digits as its factorization.

2129009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7806.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 2129009 is about 1459.1124014277. The cubic root of 2129009 is about 128.6448779031.

The spelling of 2129009 in words is "two million, one hundred twenty-nine thousand, nine".