18221531489280 has 1320 divisors, whose sum is σ = 78762421096128. Its totient is φ = 3945488154624.

The previous prime is 18221531489257. The next prime is 18221531489297. The reversal of 18221531489280 is 8298413512281.

It is a happy number.

18221531489280 is a `hidden beast` number, since 1 + 8 + 2 + 2 + 1 + 531 + 4 + 89 + 28 + 0 = 666.

It is a super-2 number, since 2×18221531489280² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1047988747 + ... + 1048006133.

Almost surely, 2^{18221531489280} is an apocalyptic number.

18221531489280 is a gapful number since it is divisible by the number (10) 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 18221531489280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39381210548064).

18221531489280 is an abundant number, since it is smaller than the sum of its proper divisors (60540889606848).

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

18221531489280 is a wasteful number, since it uses less digits than its factorization.

18221531489280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17469 (or 17423 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 54.

The spelling of 18221531489280 in words is "eighteen trillion, two hundred twenty-one billion, five hundred thirty-one million, four hundred eighty-nine thousand, two hundred eighty".