181638162072 has 128 divisors (see below), whose sum is σ = 516783801600. Its totient is φ = 59080783104.

The previous prime is 181638162061. The next prime is 181638162077. The reversal of 181638162072 is 270261836181.

181638162072 is a `hidden beast` number, since 1 + 8 + 1 + 638 + 1 + 6 + 2 + 0 + 7 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181638162077) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10180023 + ... + 10197849.

It is an arithmetic number, because the mean of its divisors is an integer number (4037373450).

Almost surely, 2^181638162072 is an apocalyptic number.

181638162072 is a gapful number since it is divisible by the number (12) 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 181638162072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258391900800).

181638162072 is an abundant number, since it is smaller than the sum of its proper divisors (335145639528).

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

181638162072 is a wasteful number, since it uses less digits than its factorization.

181638162072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18982 (or 18972 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 181638162072 in words is "one hundred eighty-one billion, six hundred thirty-eight million, one hundred sixty-two thousand, seventy-two".