20518473 has 16 divisors (see below), whose sum is σ = 29517696. Its totient is φ = 12629760.

The previous prime is 20518451. The next prime is 20518483. The reversal of 20518473 is 37481502.

It is not a de Polignac number, because 20518473 - 2⁵ = 20518441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20518473.

It is not an unprimeable number, because it can be changed into a prime (20518403) 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 15 ways as a sum of consecutive naturals, for example, 1093 + ... + 6498.

It is an arithmetic number, because the mean of its divisors is an integer number (1844856).

Almost surely, 2^20518473 is an apocalyptic number.

It is an amenable number.

20518473 is a deficient number, since it is larger than the sum of its proper divisors (8999223).

20518473 is a wasteful number, since it uses less digits than its factorization.

20518473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7664.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 20518473 is about 4529.7321112843. The cubic root of 20518473 is about 273.7673669681.

Adding to 20518473 its reverse (37481502), we get a palindrome (57999975).

The spelling of 20518473 in words is "twenty million, five hundred eighteen thousand, four hundred seventy-three".