20389121 has 4 divisors (see below), whose sum is σ = 20402244. Its totient is φ = 20376000.

The previous prime is 20389111. The next prime is 20389129. The reversal of 20389121 is 12198302.

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 2070721 + 18318400 = 1439^2 + 4280^2 .

It is a cyclic number.

It is not a de Polignac number, because 20389121 - 2²² = 16194817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20389129) 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, 3860 + ... + 7461.

It is an arithmetic number, because the mean of its divisors is an integer number (5100561).

Almost surely, 2^20389121 is an apocalyptic number.

It is an amenable number.

20389121 is a deficient number, since it is larger than the sum of its proper divisors (13123).

20389121 is a wasteful number, since it uses less digits than its factorization.

20389121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13122.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 20389121 is about 4515.4314301072. The cubic root of 20389121 is about 273.1908615367.

The spelling of 20389121 in words is "twenty million, three hundred eighty-nine thousand, one hundred twenty-one".