20353509 has 24 divisors (see below), whose sum is σ = 32471712. Its totient is φ = 12181920.

The previous prime is 20353493. The next prime is 20353511. The reversal of 20353509 is 90535302.

It is not a de Polignac number, because 20353509 - 2⁴ = 20353493 is a prime.

It is a super-2 number, since 2×20353509² = 828530657226162, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20353519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6979 + ... + 9455.

It is an arithmetic number, because the mean of its divisors is an integer number (1352988).

Almost surely, 2^20353509 is an apocalyptic number.

It is an amenable number.

20353509 is a deficient number, since it is larger than the sum of its proper divisors (12118203).

20353509 is a wasteful number, since it uses less digits than its factorization.

20353509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2577 (or 2574 counting only the distinct ones).

The product of its (nonzero) digits is 4050, while the sum is 27.

The square root of 20353509 is about 4511.4863404426. The cubic root of 20353509 is about 273.0317155119.

The spelling of 20353509 in words is "twenty million, three hundred fifty-three thousand, five hundred nine".