181827381920 has 24 divisors (see below), whose sum is σ = 429567190164. Its totient is φ = 72730952704.

The previous prime is 181827381881. The next prime is 181827381943. The reversal of 181827381920 is 29183728181.

It can be written as a sum of positive squares in 2 ways, for example, as 179067770896 + 2759611024 = 423164^2 + 52532^2 .

It is a super-2 number, since 2×181827381920² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 568210409 + ... + 568210728.

Almost surely, 2^181827381920 is an apocalyptic number.

181827381920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181827381920 is an abundant number, since it is smaller than the sum of its proper divisors (247739808244).

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

181827381920 is a wasteful number, since it uses less digits than its factorization.

181827381920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136421152 (or 1136421144 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 50.

The spelling of 181827381920 in words is "one hundred eighty-one billion, eight hundred twenty-seven million, three hundred eighty-one thousand, nine hundred twenty".