20368809 has 6 divisors (see below), whose sum is σ = 29421626. Its totient is φ = 13579200.

The previous prime is 20368793. The next prime is 20368811. The reversal of 20368809 is 90886302.

It can be written as a sum of positive squares in only one way, i.e., 17139600 + 3229209 = 4140^2 + 1797^2 .

It is not a de Polignac number, because 20368809 - 2⁴ = 20368793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20368819) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1131592 + ... + 1131609.

Almost surely, 2^20368809 is an apocalyptic number.

It is an amenable number.

20368809 is a deficient number, since it is larger than the sum of its proper divisors (9052817).

20368809 is a wasteful number, since it uses less digits than its factorization.

20368809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2263207 (or 2263204 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 20368809 is about 4513.1816936614. The cubic root of 20368809 is about 273.1001122185.

The spelling of 20368809 in words is "twenty million, three hundred sixty-eight thousand, eight hundred nine".