20018388505 has 16 divisors (see below), whose sum is σ = 26773822080. Its totient is φ = 14279369472.

The previous prime is 20018388497. The next prime is 20018388527. The reversal of 20018388505 is 50588381002.

It is a cyclic number.

It is not a de Polignac number, because 20018388505 - 2³ = 20018388497 is a prime.

It is a super-2 number, since 2×20018388505² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6196029 + ... + 6199258.

It is an arithmetic number, because the mean of its divisors is an integer number (1673363880).

Almost surely, 2^20018388505 is an apocalyptic number.

It is an amenable number.

20018388505 is a deficient number, since it is larger than the sum of its proper divisors (6755433575).

20018388505 is a wasteful number, since it uses less digits than its factorization.

20018388505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12395328.

The product of its (nonzero) digits is 76800, while the sum is 40.

The spelling of 20018388505 in words is "twenty billion, eighteen million, three hundred eighty-eight thousand, five hundred five".