181379665 has 4 divisors (see below), whose sum is σ = 217655604. Its totient is φ = 145103728.

The previous prime is 181379641. The next prime is 181379677. The reversal of 181379665 is 566973181.

It is a happy number.

181379665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 566973181 = 337 ⋅1682413.

It can be written as a sum of positive squares in 2 ways, for example, as 142491969 + 38887696 = 11937^2 + 6236^2 .

It is a cyclic number.

It is not a de Polignac number, because 181379665 - 2¹¹ = 181377617 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18137962 + ... + 18137971.

It is an arithmetic number, because the mean of its divisors is an integer number (54413901).

Almost surely, 2^181379665 is an apocalyptic number.

It is an amenable number.

181379665 is a deficient number, since it is larger than the sum of its proper divisors (36275939).

181379665 is an equidigital number, since it uses as much as digits as its factorization.

181379665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36275938.

The product of its digits is 272160, while the sum is 46.

The square root of 181379665 is about 13467.7267940807. The cubic root of 181379665 is about 566.0605189027.

The spelling of 181379665 in words is "one hundred eighty-one million, three hundred seventy-nine thousand, six hundred sixty-five".