20550805 has 16 divisors (see below), whose sum is σ = 26993088. Its totient is φ = 14896000.

The previous prime is 20550791. The next prime is 20550809. The reversal of 20550805 is 50805502.

It is not a de Polignac number, because 20550805 - 2¹¹ = 20548757 is a prime.

It is a super-2 number, since 2×20550805² = 844671172296050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20550805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20550809) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26625 + ... + 27385.

It is an arithmetic number, because the mean of its divisors is an integer number (1687068).

Almost surely, 2^20550805 is an apocalyptic number.

It is an amenable number.

20550805 is a deficient number, since it is larger than the sum of its proper divisors (6442283).

20550805 is a wasteful number, since it uses less digits than its factorization.

20550805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1268.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 20550805 is about 4533.2995709527. The cubic root of 20550805 is about 273.9110878865.

The spelling of 20550805 in words is "twenty million, five hundred fifty thousand, eight hundred five".