20611009 has 4 divisors (see below), whose sum is σ = 20918704. Its totient is φ = 20303316.

The previous prime is 20611007. The next prime is 20611033. The reversal of 20611009 is 90011602.

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 20611009 - 2¹ = 20611007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20611007) 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, 153747 + ... + 153880.

It is an arithmetic number, because the mean of its divisors is an integer number (5229676).

Almost surely, 2^20611009 is an apocalyptic number.

It is an amenable number.

20611009 is a deficient number, since it is larger than the sum of its proper divisors (307695).

20611009 is an equidigital number, since it uses as much as digits as its factorization.

20611009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307694.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 20611009 is about 4539.9349114277. The cubic root of 20611009 is about 274.1783031475.

The spelling of 20611009 in words is "twenty million, six hundred eleven thousand, nine".