18021294144 has 336 divisors, whose sum is σ = 63734411520. Its totient is φ = 4754534400.

The previous prime is 18021294131. The next prime is 18021294149. The reversal of 18021294144 is 44149212081.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18021294099 and 18021294108.

It is not an unprimeable number, because it can be changed into a prime (18021294149) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2685994 + ... + 2692694.

Almost surely, 2^18021294144 is an apocalyptic number.

18021294144 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 18021294144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31867205760).

18021294144 is an abundant number, since it is smaller than the sum of its proper divisors (45713117376).

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

18021294144 is a wasteful number, since it uses less digits than its factorization.

18021294144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6778 (or 6765 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 18021294144 in words is "eighteen billion, twenty-one million, two hundred ninety-four thousand, one hundred forty-four".