20383921 has 4 divisors (see below), whose sum is σ = 20585844. Its totient is φ = 20182000.

The previous prime is 20383907. The next prime is 20383927. The reversal of 20383921 is 12938302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13957696 + 6426225 = 3736^2 + 2535^2 .

It is a cyclic number.

It is not a de Polignac number, because 20383921 - 2¹⁵ = 20351153 is a prime.

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 20383921.

It is not an unprimeable number, because it can be changed into a prime (20383927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100810 + ... + 101011.

It is an arithmetic number, because the mean of its divisors is an integer number (5146461).

Almost surely, 2^20383921 is an apocalyptic number.

It is an amenable number.

20383921 is a deficient number, since it is larger than the sum of its proper divisors (201923).

20383921 is a wasteful number, since it uses less digits than its factorization.

20383921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201922.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20383921 is about 4514.8555901601. The cubic root of 20383921 is about 273.1676348813.

The spelling of 20383921 in words is "twenty million, three hundred eighty-three thousand, nine hundred twenty-one".