18531980544 has 432 divisors, whose sum is σ = 64026583040. Its totient is φ = 4653158400.

The previous prime is 18531980527. The next prime is 18531980561. The reversal of 18531980544 is 44508913581.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18531980527) and next prime (18531980561).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 18531980493 and 18531980502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20164917 + ... + 20165835.

Almost surely, 2^18531980544 is an apocalyptic number.

18531980544 is a gapful number since it is divisible by the number (14) 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 18531980544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32013291520).

18531980544 is an abundant number, since it is smaller than the sum of its proper divisors (45494602496).

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

18531980544 is a wasteful number, since it uses less digits than its factorization.

18531980544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 48.

The spelling of 18531980544 in words is "eighteen billion, five hundred thirty-one million, nine hundred eighty thousand, five hundred forty-four".