20210009 has 4 divisors (see below), whose sum is σ = 20247504. Its totient is φ = 20172516.

The previous prime is 20209993. The next prime is 20210023. The reversal of 20210009 is 90001202.

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 20210009 - 2⁴ = 20209993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20209975 and 20210002.

It is not an unprimeable number, because it can be changed into a prime (20210039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17927 + ... + 19020.

It is an arithmetic number, because the mean of its divisors is an integer number (5061876).

Almost surely, 2^20210009 is an apocalyptic number.

It is an amenable number.

20210009 is a deficient number, since it is larger than the sum of its proper divisors (37495).

20210009 is an equidigital number, since it uses as much as digits as its factorization.

20210009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37494.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 20210009 is about 4495.5543595868. The cubic root of 20210009 is about 272.3885423595.

The spelling of 20210009 in words is "twenty million, two hundred ten thousand, nine".