181664736 has 48 divisors (see below), whose sum is σ = 520224768. Its totient is φ = 55049600.

The previous prime is 181664711. The next prime is 181664767. The reversal of 181664736 is 637466181.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-6 number, since 6×181664736⁶ (a number of 51 digits) contains 666666 as substring.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 84960 + ... + 87071.

It is an arithmetic number, because the mean of its divisors is an integer number (10838016).

Almost surely, 2^181664736 is an apocalyptic number.

181664736 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

181664736 is an abundant number, since it is smaller than the sum of its proper divisors (338560032).

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

181664736 is a wasteful number, since it uses less digits than its factorization.

181664736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172055 (or 172047 counting only the distinct ones).

The product of its digits is 145152, while the sum is 42.

The square root of 181664736 is about 13478.3061250292. The cubic root of 181664736 is about 566.3569192232.

The spelling of 181664736 in words is "one hundred eighty-one million, six hundred sixty-four thousand, seven hundred thirty-six".