20018913 has 16 divisors (see below), whose sum is σ = 28288320. Its totient is φ = 12557376.

The previous prime is 20018909. The next prime is 20018923. The reversal of 20018913 is 31981002.

It is not a de Polignac number, because 20018913 - 2² = 20018909 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20018923) 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 15 ways as a sum of consecutive naturals, for example, 7831 + ... + 10067.

It is an arithmetic number, because the mean of its divisors is an integer number (1768020).

Almost surely, 2^20018913 is an apocalyptic number.

It is an amenable number.

20018913 is a deficient number, since it is larger than the sum of its proper divisors (8269407).

20018913 is a wasteful number, since it uses less digits than its factorization.

20018913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2416.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 20018913 is about 4474.2499930156. The cubic root of 20018913 is about 271.5272976701.

Adding to 20018913 its reverse (31981002), we get a palindrome (51999915).

The spelling of 20018913 in words is "twenty million, eighteen thousand, nine hundred thirteen".