181398666 has 8 divisors (see below), whose sum is σ = 362797344. Its totient is φ = 60466220.

The previous prime is 181398661. The next prime is 181398673. The reversal of 181398666 is 666893181.

It is a sphenic number, since it is the product of 3 distinct primes.

181398666 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (181398661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15116550 + ... + 15116561.

It is an arithmetic number, because the mean of its divisors is an integer number (45349668).

Almost surely, 2^181398666 is an apocalyptic number.

181398666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

181398666 is a wasteful number, since it uses less digits than its factorization.

181398666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30233116.

The product of its digits is 373248, while the sum is 48.

The square root of 181398666 is about 13468.4322027473. The cubic root of 181398666 is about 566.0802846987.

The spelling of 181398666 in words is "one hundred eighty-one million, three hundred ninety-eight thousand, six hundred sixty-six".