181996784640 has 1056 divisors, whose sum is σ = 731694352896. Its totient is φ = 41393848320.

The previous prime is 181996784537. The next prime is 181996784687. The reversal of 181996784640 is 46487699181.

181996784640 is a `hidden beast` number, since 1 + 8 + 19 + 96 + 78 + 464 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1056).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 781101964 + ... + 781102196.

Almost surely, 2^181996784640 is an apocalyptic number.

181996784640 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 181996784640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (365847176448).

181996784640 is an abundant number, since it is smaller than the sum of its proper divisors (549697568256).

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

181996784640 is a wasteful number, since it uses less digits than its factorization.

181996784640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 20901888, while the sum is 63.

The spelling of 181996784640 in words is "one hundred eighty-one billion, nine hundred ninety-six million, seven hundred eighty-four thousand, six hundred forty".