181036985 has 4 divisors (see below), whose sum is σ = 217244388. Its totient is φ = 144829584.

The previous prime is 181036981. The next prime is 181036987. The reversal of 181036985 is 589630181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69438889 + 111598096 = 8333^2 + 10564^2 .

It is a cyclic number.

It is not a de Polignac number, because 181036985 - 2² = 181036981 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181036981) 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, 18103694 + ... + 18103703.

It is an arithmetic number, because the mean of its divisors is an integer number (54311097).

Almost surely, 2^181036985 is an apocalyptic number.

It is an amenable number.

181036985 is a deficient number, since it is larger than the sum of its proper divisors (36207403).

181036985 is an equidigital number, since it uses as much as digits as its factorization.

181036985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36207402.

The product of its (nonzero) digits is 51840, while the sum is 41.

The square root of 181036985 is about 13454.9985135636. The cubic root of 181036985 is about 565.7038087437.

The spelling of 181036985 in words is "one hundred eighty-one million, thirty-six thousand, nine hundred eighty-five".