181866157 has 8 divisors (see below), whose sum is σ = 208841760. Its totient is φ = 156630960.

The previous prime is 181866151. The next prime is 181866227. The reversal of 181866157 is 751668181.

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

It is a cyclic number.

It is not a de Polignac number, because 181866157 - 2¹⁵ = 181833389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181866151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 434878 + ... + 435295.

It is an arithmetic number, because the mean of its divisors is an integer number (26105220).

Almost surely, 2^181866157 is an apocalyptic number.

It is an amenable number.

181866157 is a deficient number, since it is larger than the sum of its proper divisors (26975603).

181866157 is a wasteful number, since it uses less digits than its factorization.

181866157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870203.

The product of its digits is 80640, while the sum is 43.

The square root of 181866157 is about 13485.7760992833. The cubic root of 181866157 is about 566.5661582218.

The spelling of 181866157 in words is "one hundred eighty-one million, eight hundred sixty-six thousand, one hundred fifty-seven".