20643854 has 32 divisors (see below), whose sum is σ = 39661056. Its totient is φ = 7823520.

The previous prime is 20643851. The next prime is 20643893. The reversal of 20643854 is 45834602.

It is a self number, because there is not a number n which added to its sum of digits gives 20643854.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643851) 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, 3887 + ... + 7509.

It is an arithmetic number, because the mean of its divisors is an integer number (1239408).

Almost surely, 2^20643854 is an apocalyptic number.

20643854 is a deficient number, since it is larger than the sum of its proper divisors (19017202).

20643854 is a wasteful number, since it uses less digits than its factorization.

20643854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3680.

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 20643854 is about 4543.5508140660. The cubic root of 20643854 is about 274.3238662466.

The spelling of 20643854 in words is "twenty million, six hundred forty-three thousand, eight hundred fifty-four".