20418973889 has 4 divisors (see below), whose sum is σ = 20420673924. Its totient is φ = 20417273856.

The previous prime is 20418973871. The next prime is 20418973901. The reversal of 20418973889 is 98837981402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 366148225 + 20052825664 = 19135^2 + 141608^2 .

It is a cyclic number.

It is not a de Polignac number, because 20418973889 - 2³² = 16124006593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20418973849) 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 3 ways as a sum of consecutive naturals, for example, 831872 + ... + 856065.

It is an arithmetic number, because the mean of its divisors is an integer number (5105168481).

Almost surely, 2^20418973889 is an apocalyptic number.

It is an amenable number.

20418973889 is a deficient number, since it is larger than the sum of its proper divisors (1700035).

20418973889 is a wasteful number, since it uses less digits than its factorization.

20418973889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700034.

The product of its (nonzero) digits is 6967296, while the sum is 59.

The spelling of 20418973889 in words is "twenty billion, four hundred eighteen million, nine hundred seventy-three thousand, eight hundred eighty-nine".