20504311 has 4 divisors (see below), whose sum is σ = 20520000. Its totient is φ = 20488624.

The previous prime is 20504221. The next prime is 20504353. The reversal of 20504311 is 11340502.

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

It is a cyclic number.

It is not a de Polignac number, because 20504311 - 2¹¹ = 20502263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20504381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5686 + ... + 8563.

It is an arithmetic number, because the mean of its divisors is an integer number (5130000).

Almost surely, 2^20504311 is an apocalyptic number.

20504311 is a deficient number, since it is larger than the sum of its proper divisors (15689).

20504311 is a wasteful number, since it uses less digits than its factorization.

20504311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15688.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 20504311 is about 4528.1686143517. The cubic root of 20504311 is about 273.7043670591.

Adding to 20504311 its reverse (11340502), we get a palindrome (31844813).

The spelling of 20504311 in words is "twenty million, five hundred four thousand, three hundred eleven".