18881533440 has 960 divisors, whose sum is σ = 84568872960. Its totient is φ = 3777822720.

The previous prime is 18881533399. The next prime is 18881533493. The reversal of 18881533440 is 4433518881.

18881533440 is a `hidden beast` number, since 1 + 88 + 81 + 53 + 3 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 51448137 + ... + 51448503.

It is an arithmetic number, because the mean of its divisors is an integer number (88092576).

Almost surely, 2^18881533440 is an apocalyptic number.

18881533440 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 18881533440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42284436480).

18881533440 is an abundant number, since it is smaller than the sum of its proper divisors (65687339520).

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

18881533440 is a wasteful number, since it uses less digits than its factorization.

18881533440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 18881533440 in words is "eighteen billion, eight hundred eighty-one million, five hundred thirty-three thousand, four hundred forty".