20018317720 has 32 divisors (see below), whose sum is σ = 46999530720. Its totient is φ = 7659182080.

The previous prime is 20018317633. The next prime is 20018317721. The reversal of 20018317720 is 2771381002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20018317721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10878601 + ... + 10880440.

It is an arithmetic number, because the mean of its divisors is an integer number (1468735335).

Almost surely, 2^20018317720 is an apocalyptic number.

20018317720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20018317720 is an abundant number, since it is smaller than the sum of its proper divisors (26981213000).

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

20018317720 is a wasteful number, since it uses less digits than its factorization.

20018317720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21759075 (or 21759071 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 31.

Adding to 20018317720 its reverse (2771381002), we get a palindrome (22789698722).

The spelling of 20018317720 in words is "twenty billion, eighteen million, three hundred seventeen thousand, seven hundred twenty".