20115563 has 6 divisors (see below), whose sum is σ = 21782124. Its totient is φ = 18568056.

The previous prime is 20115553. The next prime is 20115583. The reversal of 20115563 is 36551102.

It is not a de Polignac number, because 20115563 - 2⁸ = 20115307 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20115503) 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 5 ways as a sum of consecutive naturals, for example, 59345 + ... + 59682.

It is an arithmetic number, because the mean of its divisors is an integer number (3630354).

Almost surely, 2^20115563 is an apocalyptic number.

20115563 is a deficient number, since it is larger than the sum of its proper divisors (1666561).

20115563 is a wasteful number, since it uses less digits than its factorization.

20115563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119053 (or 119040 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 20115563 is about 4485.0376810011. The cubic root of 20115563 is about 271.9635683256.

Adding to 20115563 its reverse (36551102), we get a palindrome (56666665).

The spelling of 20115563 in words is "twenty million, one hundred fifteen thousand, five hundred sixty-three".