20420918538 has 8 divisors (see below), whose sum is σ = 40841837088. Its totient is φ = 6806972844.

The previous prime is 20420918533. The next prime is 20420918549. The reversal of 20420918538 is 83581902402.

It is a sphenic number, since it is the product of 3 distinct primes.

20420918538 is an admirable number.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 20420918538.

It is not an unprimeable number, because it can be changed into a prime (20420918533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1701743206 + ... + 1701743217.

It is an arithmetic number, because the mean of its divisors is an integer number (5105229636).

Almost surely, 2^20420918538 is an apocalyptic number.

20420918538 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20420918538 is a wasteful number, since it uses less digits than its factorization.

20420918538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3403486428.

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 20420918538 in words is "twenty billion, four hundred twenty million, nine hundred eighteen thousand, five hundred thirty-eight".