181000664 has 64 divisors (see below), whose sum is σ = 376434240. Its totient is φ = 81077760.

The previous prime is 181000663. The next prime is 181000667. The reversal of 181000664 is 466000181.

181000664 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×181000664² = 65522480736881792, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181000663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 653294 + ... + 653570.

It is an arithmetic number, because the mean of its divisors is an integer number (5881785).

Almost surely, 2^181000664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181000664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188217120).

181000664 is an abundant number, since it is smaller than the sum of its proper divisors (195433576).

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

181000664 is a wasteful number, since it uses less digits than its factorization.

181000664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460 (or 456 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 181000664 is about 13453.6487244167. The cubic root of 181000664 is about 565.6659742974.

The spelling of 181000664 in words is "one hundred eighty-one million, six hundred sixty-four", and thus it is an aban number.