20504947 has 4 divisors (see below), whose sum is σ = 20618416. Its totient is φ = 20391480.

The previous prime is 20504923. The next prime is 20504959. The reversal of 20504947 is 74940502.

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 20504947 - 2¹⁹ = 19980659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20504917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56463 + ... + 56824.

It is an arithmetic number, because the mean of its divisors is an integer number (5154604).

Almost surely, 2^20504947 is an apocalyptic number.

20504947 is a deficient number, since it is larger than the sum of its proper divisors (113469).

20504947 is a wasteful number, since it uses less digits than its factorization.

20504947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113468.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20504947 is about 4528.2388408740. The cubic root of 20504947 is about 273.7071969385.

The spelling of 20504947 in words is "twenty million, five hundred four thousand, nine hundred forty-seven".