20885921 has 8 divisors (see below), whose sum is σ = 25126080. Its totient is φ = 16959888.

The previous prime is 20885873. The next prime is 20885927. The reversal of 20885921 is 12958802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20885921 - 2¹⁸ = 20623777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20885927) 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 7 ways as a sum of consecutive naturals, for example, 78386 + ... + 78651.

It is an arithmetic number, because the mean of its divisors is an integer number (3140760).

Almost surely, 2^20885921 is an apocalyptic number.

It is an amenable number.

20885921 is a deficient number, since it is larger than the sum of its proper divisors (4240159).

20885921 is a wasteful number, since it uses less digits than its factorization.

20885921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157063.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 20885921 is about 4570.1117054182. Note that the first 3 decimals coincide. The cubic root of 20885921 is about 275.3919304110.

The spelling of 20885921 in words is "twenty million, eight hundred eighty-five thousand, nine hundred twenty-one".