20236813 has 4 divisors (see below), whose sum is σ = 20246688. Its totient is φ = 20226940.

The previous prime is 20236807. The next prime is 20236861. The reversal of 20236813 is 31863202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20236813 - 2⁵ = 20236781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20237813) 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 3 ways as a sum of consecutive naturals, for example, 583 + ... + 6388.

It is an arithmetic number, because the mean of its divisors is an integer number (5061672).

Almost surely, 2^20236813 is an apocalyptic number.

It is an amenable number.

20236813 is a deficient number, since it is larger than the sum of its proper divisors (9875).

20236813 is an equidigital number, since it uses as much as digits as its factorization.

20236813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9874.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20236813 is about 4498.5345391583. The cubic root of 20236813 is about 272.5089097331.

It can be divided in two parts, 2023 and 6813, that added together give a square (8836 = 94²).

The spelling of 20236813 in words is "twenty million, two hundred thirty-six thousand, eight hundred thirteen".