20205123 has 8 divisors (see below), whose sum is σ = 27342528. Its totient is φ = 13268904.

The previous prime is 20205121. The next prime is 20205139. The reversal of 20205123 is 32150202.

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

It is not a de Polignac number, because 20205123 - 2¹ = 20205121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20205121) 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 7 ways as a sum of consecutive naturals, for example, 50061 + ... + 50462.

It is an arithmetic number, because the mean of its divisors is an integer number (3417816).

Almost surely, 2^20205123 is an apocalyptic number.

20205123 is a deficient number, since it is larger than the sum of its proper divisors (7137405).

20205123 is a wasteful number, since it uses less digits than its factorization.

20205123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100593.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 20205123 is about 4495.0109009879. The cubic root of 20205123 is about 272.3665895788.

Adding to 20205123 its reverse (32150202), we get a palindrome (52355325).

The spelling of 20205123 in words is "twenty million, two hundred five thousand, one hundred twenty-three".