20508418509 has 16 divisors (see below), whose sum is σ = 27402661632. Its totient is φ = 13643255808.

The previous prime is 20508418507. The next prime is 20508418519. The reversal of 20508418509 is 90581480502.

It is a happy number.

It is not a de Polignac number, because 20508418509 - 2¹ = 20508418507 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20508418507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5362572 + ... + 5366394.

It is an arithmetic number, because the mean of its divisors is an integer number (1712666352).

Almost surely, 2^20508418509 is an apocalyptic number.

It is an amenable number.

20508418509 is a deficient number, since it is larger than the sum of its proper divisors (6894243123).

20508418509 is a wasteful number, since it uses less digits than its factorization.

20508418509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7156.

The product of its (nonzero) digits is 115200, while the sum is 42.

The spelling of 20508418509 in words is "twenty billion, five hundred eight million, four hundred eighteen thousand, five hundred nine".