18449881920 has 448 divisors, whose sum is σ = 67602689280. Its totient is φ = 4792504320.

The previous prime is 18449881897. The next prime is 18449881949. The reversal of 18449881920 is 2918894481.

It is a happy number.

18449881920 is a `hidden beast` number, since 1 + 8 + 449 + 8 + 8 + 192 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 28693119 + ... + 28693761.

It is an arithmetic number, because the mean of its divisors is an integer number (150898860).

Almost surely, 2^18449881920 is an apocalyptic number.

18449881920 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 18449881920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33801344640).

18449881920 is an abundant number, since it is smaller than the sum of its proper divisors (49152807360).

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

18449881920 is an frugal number, since it uses more digits than its factorization.

18449881920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722 (or 694 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The spelling of 18449881920 in words is "eighteen billion, four hundred forty-nine million, eight hundred eighty-one thousand, nine hundred twenty".