20309811 has 4 divisors (see below), whose sum is σ = 27079752. Its totient is φ = 13539872.

The previous prime is 20309797. The next prime is 20309827. The reversal of 20309811 is 11890302.

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

It is a cyclic number.

It is not a de Polignac number, because 20309811 - 2⁷ = 20309683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20304811) 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, 3384966 + ... + 3384971.

It is an arithmetic number, because the mean of its divisors is an integer number (6769938).

Almost surely, 2^20309811 is an apocalyptic number.

20309811 is a deficient number, since it is larger than the sum of its proper divisors (6769941).

20309811 is an equidigital number, since it uses as much as digits as its factorization.

20309811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6769940.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 20309811 is about 4506.6407666909. The cubic root of 20309811 is about 272.8361802115.

The spelling of 20309811 in words is "twenty million, three hundred nine thousand, eight hundred eleven".