181323220320 has 288 divisors, whose sum is σ = 680177481984. Its totient is φ = 43621094400.

The previous prime is 181323220303. The next prime is 181323220357. The reversal of 181323220320 is 23022323181.

It is a happy number.

181323220320 is a `hidden beast` number, since 1 + 8 + 13 + 2 + 322 + 0 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×181323220320² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2031349 + ... + 2118731.

It is an arithmetic number, because the mean of its divisors is an integer number (2361727368).

Almost surely, 2^181323220320 is an apocalyptic number.

181323220320 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 181323220320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (340088740992).

181323220320 is an abundant number, since it is smaller than the sum of its proper divisors (498854261664).

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

181323220320 is a wasteful number, since it uses less digits than its factorization.

181323220320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87546 (or 87535 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The spelling of 181323220320 in words is "one hundred eighty-one billion, three hundred twenty-three million, two hundred twenty thousand, three hundred twenty".