20351009 has 4 divisors (see below), whose sum is σ = 23258304. Its totient is φ = 17443716.

The previous prime is 20350991. The next prime is 20351017. The reversal of 20351009 is 90015302.

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 20351009 - 2⁸ = 20350753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20351029) 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, 1453637 + ... + 1453650.

It is an arithmetic number, because the mean of its divisors is an integer number (5814576).

Almost surely, 2^20351009 is an apocalyptic number.

It is an amenable number.

20351009 is a deficient number, since it is larger than the sum of its proper divisors (2907295).

20351009 is an equidigital number, since it uses as much as digits as its factorization.

20351009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2907294.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 20351009 is about 4511.2092613844. The cubic root of 20351009 is about 273.0205363218.

The spelling of 20351009 in words is "twenty million, three hundred fifty-one thousand, nine".