20268309 has 16 divisors (see below), whose sum is σ = 27820800. Its totient is φ = 13117440.

The previous prime is 20268293. The next prime is 20268317. The reversal of 20268309 is 90386202.

20268309 = 683² + 684² + ... + 723².

It is not a de Polignac number, because 20268309 - 2⁴ = 20268293 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20268379) 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 15 ways as a sum of consecutive naturals, for example, 44917 + ... + 45365.

It is an arithmetic number, because the mean of its divisors is an integer number (1738800).

Almost surely, 2^20268309 is an apocalyptic number.

It is an amenable number.

20268309 is a deficient number, since it is larger than the sum of its proper divisors (7552491).

20268309 is a wasteful number, since it uses less digits than its factorization.

20268309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 20268309 is about 4502.0338737064. The cubic root of 20268309 is about 272.6502114904.

The spelling of 20268309 in words is "twenty million, two hundred sixty-eight thousand, three hundred nine".