20550813 has 4 divisors (see below), whose sum is σ = 27401088. Its totient is φ = 13700540.

The previous prime is 20550809. The next prime is 20550857. The reversal of 20550813 is 31805502.

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.

It is a cyclic number.

It is not a de Polignac number, because 20550813 - 2² = 20550809 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20550863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3425133 + ... + 3425138.

It is an arithmetic number, because the mean of its divisors is an integer number (6850272).

Almost surely, 2^20550813 is an apocalyptic number.

It is an amenable number.

20550813 is a deficient number, since it is larger than the sum of its proper divisors (6850275).

20550813 is an equidigital number, since it uses as much as digits as its factorization.

20550813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6850274.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 20550813 is about 4533.3004533121. The cubic root of 20550813 is about 273.9111234291.

The spelling of 20550813 in words is "twenty million, five hundred fifty thousand, eight hundred thirteen".