181990534320 has 1120 divisors, whose sum is σ = 757400523264. Its totient is φ = 39788236800.

The previous prime is 181990534289. The next prime is 181990534409. The reversal of 181990534320 is 23435099181.

It is a happy number.

181990534320 is a `hidden beast` number, since 1 + 8 + 1 + 9 + 90 + 534 + 3 + 20 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 1389240655 + ... + 1389240785.

Almost surely, 2^181990534320 is an apocalyptic number.

181990534320 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 181990534320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (378700261632).

181990534320 is an abundant number, since it is smaller than the sum of its proper divisors (575409988944).

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

181990534320 is a wasteful number, since it uses less digits than its factorization.

181990534320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 272 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 181990534320 in words is "one hundred eighty-one billion, nine hundred ninety million, five hundred thirty-four thousand, three hundred twenty".