181381607 has 4 divisors (see below), whose sum is σ = 197870856. Its totient is φ = 164892360.

The previous prime is 181381597. The next prime is 181381621. The reversal of 181381607 is 706183181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 706183181 = 11 ⋅64198471.

It is a cyclic number.

It is not a de Polignac number, because 181381607 - 2¹⁰ = 181380583 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 (181381667) 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, 8244608 + ... + 8244629.

It is an arithmetic number, because the mean of its divisors is an integer number (49467714).

Almost surely, 2^181381607 is an apocalyptic number.

181381607 is a deficient number, since it is larger than the sum of its proper divisors (16489249).

181381607 is a wasteful number, since it uses less digits than its factorization.

181381607 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16489248.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 181381607 is about 13467.7988921724. The cubic root of 181381607 is about 566.0625391321.

The spelling of 181381607 in words is "one hundred eighty-one million, three hundred eighty-one thousand, six hundred seven".