181428387840 has 1344 divisors, whose sum is σ = 783916038720. Its totient is φ = 40131624960.

The previous prime is 181428387799. The next prime is 181428387859. The reversal of 181428387840 is 48783824181.

181428387840 is a `hidden beast` number, since 1 + 81 + 428 + 38 + 78 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

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 83 ways as a sum of consecutive naturals, for example, 5852528625 + ... + 5852528655.

Almost surely, 2^181428387840 is an apocalyptic number.

181428387840 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 181428387840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391958019360).

181428387840 is an abundant number, since it is smaller than the sum of its proper divisors (602487650880).

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

181428387840 is an frugal number, since it uses more digits than its factorization.

181428387840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98 (or 48 counting only the distinct ones).

The product of its (nonzero) digits is 2752512, while the sum is 54.

The spelling of 181428387840 in words is "one hundred eighty-one billion, four hundred twenty-eight million, three hundred eighty-seven thousand, eight hundred forty".