181921500475680 has 384 divisors, whose sum is σ = 663037820121600. Its totient is φ = 41068913393664.

The previous prime is 181921500475639. The next prime is 181921500475717. The reversal of 181921500475680 is 86574005129181.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 181921500475680.

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, 113839626 + ... + 115426614.

It is an arithmetic number, because the mean of its divisors is an integer number (1726660989900).

Almost surely, 2^{181921500475680} is an apocalyptic number.

181921500475680 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 181921500475680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (331518910060800).

181921500475680 is an abundant number, since it is smaller than the sum of its proper divisors (481116319645920).

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

181921500475680 is a wasteful number, since it uses less digits than its factorization.

181921500475680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1587436 (or 1587428 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 57.

The spelling of 181921500475680 in words is "one hundred eighty-one trillion, nine hundred twenty-one billion, five hundred million, four hundred seventy-five thousand, six hundred eighty".