20518456 has 48 divisors (see below), whose sum is σ = 47401200. Its totient is φ = 8273664.

The previous prime is 20518451. The next prime is 20518483. The reversal of 20518456 is 65481502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20518451) 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 11 ways as a sum of consecutive naturals, for example, 5125 + ... + 8203.

It is an arithmetic number, because the mean of its divisors is an integer number (987525).

Almost surely, 2^20518456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20518456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23700600).

20518456 is an abundant number, since it is smaller than the sum of its proper divisors (26882744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20518456 is a wasteful number, since it uses less digits than its factorization.

20518456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3116 (or 3105 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 31.

The square root of 20518456 is about 4529.7302347932. The cubic root of 20518456 is about 273.7672913607.

Adding to 20518456 its reverse (65481502), we get a palindrome (85999958).

The spelling of 20518456 in words is "twenty million, five hundred eighteen thousand, four hundred fifty-six".