20018531568 has 120 divisors (see below), whose sum is σ = 61211483008. Its totient is φ = 5522275584.

The previous prime is 20018531557. The next prime is 20018531581. The reversal of 20018531568 is 86513581002.

It is a super-2 number, since 2×20018531568² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 247155 + ... + 317997.

Almost surely, 2^20018531568 is an apocalyptic number.

20018531568 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20018531568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30605741504).

20018531568 is an abundant number, since it is smaller than the sum of its proper divisors (41192951440).

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

20018531568 is a wasteful number, since it uses less digits than its factorization.

20018531568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70919 (or 70884 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 39.

The spelling of 20018531568 in words is "twenty billion, eighteen million, five hundred thirty-one thousand, five hundred sixty-eight".