20275309 has 4 divisors (see below), whose sum is σ = 20657916. Its totient is φ = 19892704.

The previous prime is 20275289. The next prime is 20275313. The reversal of 20275309 is 90357202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8352100 + 11923209 = 2890^2 + 3453^2 .

It is a cyclic number.

It is not a de Polignac number, because 20275309 - 2⁷ = 20275181 is a prime.

It is a super-2 number, since 2×20275309² = 822176310090962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20275349) 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, 191224 + ... + 191329.

It is an arithmetic number, because the mean of its divisors is an integer number (5164479).

Almost surely, 2^20275309 is an apocalyptic number.

It is an amenable number.

20275309 is a deficient number, since it is larger than the sum of its proper divisors (382607).

20275309 is an equidigital number, since it uses as much as digits as its factorization.

20275309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382606.

The product of its (nonzero) digits is 3780, while the sum is 28.

The square root of 20275309 is about 4502.8112329966. The cubic root of 20275309 is about 272.6815959834.

The spelling of 20275309 in words is "twenty million, two hundred seventy-five thousand, three hundred nine".