181816901280 has 576 divisors, whose sum is σ = 776707626240. Its totient is φ = 37763776512.

The previous prime is 181816901213. The next prime is 181816901291. The reversal of 181816901280 is 82109618181.

It is a super-2 number, since 2×181816901280² (a number of 23 digits) contains 22 as substring.

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

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, 4951147 + ... + 4987733.

It is an arithmetic number, because the mean of its divisors is an integer number (1348450740).

Almost surely, 2^181816901280 is an apocalyptic number.

181816901280 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 181816901280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (388353813120).

181816901280 is an abundant number, since it is smaller than the sum of its proper divisors (594890724960).

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

181816901280 is a wasteful number, since it uses less digits than its factorization.

181816901280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36661 (or 36650 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 45.

The spelling of 181816901280 in words is "one hundred eighty-one billion, eight hundred sixteen million, nine hundred one thousand, two hundred eighty".