181840220028 has 60 divisors (see below), whose sum is σ = 477260357112. Its totient is φ = 60371892000.

The previous prime is 181840220021. The next prime is 181840220039. The reversal of 181840220028 is 820022048181.

181840220028 is a `hidden beast` number, since 18 + 18 + 402 + 200 + 28 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 181840219974 and 181840220001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181840220021) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1036675 + ... + 1199322.

Almost surely, 2^181840220028 is an apocalyptic number.

181840220028 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

181840220028 is an abundant number, since it is smaller than the sum of its proper divisors (295420137084).

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

181840220028 is a wasteful number, since it uses less digits than its factorization.

181840220028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2236264 (or 2236253 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 36.

The spelling of 181840220028 in words is "one hundred eighty-one billion, eight hundred forty million, two hundred twenty thousand, twenty-eight".