181485521 has 4 divisors (see below), whose sum is σ = 207412032. Its totient is φ = 155559012.

The previous prime is 181485467. The next prime is 181485527. The reversal of 181485521 is 125584181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 125584181 = 29 ⋅4330489.

It is not a de Polignac number, because 181485521 - 2⁶ = 181485457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (181485527) 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, 12963245 + ... + 12963258.

It is an arithmetic number, because the mean of its divisors is an integer number (51853008).

Almost surely, 2^181485521 is an apocalyptic number.

It is an amenable number.

181485521 is a deficient number, since it is larger than the sum of its proper divisors (25926511).

181485521 is an equidigital number, since it uses as much as digits as its factorization.

181485521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25926510.

The product of its digits is 12800, while the sum is 35.

The square root of 181485521 is about 13471.6562084994. The cubic root of 181485521 is about 566.1706180680.

The spelling of 181485521 in words is "one hundred eighty-one million, four hundred eighty-five thousand, five hundred twenty-one".