18020431616 has 144 divisors (see below), whose sum is σ = 40085031168. Its totient is φ = 8016691200.

The previous prime is 18020431609. The next prime is 18020431619. The reversal of 18020431616 is 61613402081.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18020431619) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38587415 + ... + 38587881.

It is an arithmetic number, because the mean of its divisors is an integer number (278368272).

Almost surely, 2^18020431616 is an apocalyptic number.

18020431616 is a gapful number since it is divisible by the number (16) 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 18020431616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20042515584).

18020431616 is an abundant number, since it is smaller than the sum of its proper divisors (22064599552).

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

18020431616 is a wasteful number, since it uses less digits than its factorization.

18020431616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758 (or 744 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

Adding to 18020431616 its reverse (61613402081), we get a palindrome (79633833697).

The spelling of 18020431616 in words is "eighteen billion, twenty million, four hundred thirty-one thousand, six hundred sixteen".