20504123 has 4 divisors (see below), whose sum is σ = 20521320. Its totient is φ = 20486928.

The previous prime is 20504119. The next prime is 20504129. The reversal of 20504123 is 32140502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32140502 = 2 ⋅16070251.

It is a cyclic number.

It is not a de Polignac number, because 20504123 - 2² = 20504119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20504129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6665 + ... + 9242.

It is an arithmetic number, because the mean of its divisors is an integer number (5130330).

Almost surely, 2^20504123 is an apocalyptic number.

20504123 is a deficient number, since it is larger than the sum of its proper divisors (17197).

20504123 is a wasteful number, since it uses less digits than its factorization.

20504123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17196.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20504123 is about 4528.1478553598. The cubic root of 20504123 is about 273.7035305427.

Adding to 20504123 its reverse (32140502), we get a palindrome (52644625).

The spelling of 20504123 in words is "twenty million, five hundred four thousand, one hundred twenty-three".