20893821 has 16 divisors (see below), whose sum is σ = 31307136. Its totient is φ = 12298176.

The previous prime is 20893811. The next prime is 20893849. The reversal of 20893821 is 12839802.

It is not a de Polignac number, because 20893821 - 2⁶ = 20893757 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20893811) 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, 10750 + ... + 12543.

It is an arithmetic number, because the mean of its divisors is an integer number (1956696).

Almost surely, 2^20893821 is an apocalyptic number.

It is an amenable number.

20893821 is a deficient number, since it is larger than the sum of its proper divisors (10413315).

20893821 is a wasteful number, since it uses less digits than its factorization.

20893821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23332.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 20893821 is about 4570.9759351806. The cubic root of 20893821 is about 275.4266479289.

The spelling of 20893821 in words is "twenty million, eight hundred ninety-three thousand, eight hundred twenty-one".