181358138 has 8 divisors (see below), whose sum is σ = 292963188. Its totient is φ = 83703744.

The previous prime is 181358137. The next prime is 181358143. The reversal of 181358138 is 831853181.

It can be written as a sum of positive squares in 2 ways, for example, as 181090849 + 267289 = 13457^2 + 517^2 .

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

It is not an unprimeable number, because it can be changed into a prime (181358137) 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, 3487631 + ... + 3487682.

Almost surely, 2^181358138 is an apocalyptic number.

181358138 is a deficient number, since it is larger than the sum of its proper divisors (111605050).

181358138 is a wasteful number, since it uses less digits than its factorization.

181358138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6975328.

The product of its digits is 23040, while the sum is 38.

The square root of 181358138 is about 13466.9275634794. The cubic root of 181358138 is about 566.0381237665.

The spelling of 181358138 in words is "one hundred eighty-one million, three hundred fifty-eight thousand, one hundred thirty-eight".