181000666 has 64 divisors (see below), whose sum is σ = 366280704. Its totient is φ = 64915200.

The previous prime is 181000663. The next prime is 181000667. The reversal of 181000666 is 666000181.

It is a super-2 number, since 2×181000666² = 65522482184887112, which contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 122311 + ... + 123781.

It is an arithmetic number, because the mean of its divisors is an integer number (5723136).

Almost surely, 2^181000666 is an apocalyptic number.

181000666 is an abundant number, since it is smaller than the sum of its proper divisors (185280038).

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

181000666 is a wasteful number, since it uses less digits than its factorization.

181000666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1555.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 181000666 is about 13453.6487987460. The cubic root of 181000666 is about 565.6659763808.

The spelling of 181000666 in words is "one hundred eighty-one million, six hundred sixty-six", and thus it is an aban number.