181601216 has 14 divisors (see below), whose sum is σ = 360365040. Its totient is φ = 90800576.

The previous prime is 181601213. The next prime is 181601243. The reversal of 181601216 is 612106181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181601213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1418696 + ... + 1418823.

It is an arithmetic number, because the mean of its divisors is an integer number (25740360).

Almost surely, 2^181601216 is an apocalyptic number.

181601216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

181601216 is a deficient number, since it is larger than the sum of its proper divisors (178763824).

181601216 is an equidigital number, since it uses as much as digits as its factorization.

181601216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2837531 (or 2837521 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 181601216 is about 13475.9495398284. The cubic root of 181601216 is about 566.2909016679.

Adding to 181601216 its reverse (612106181), we get a palindrome (793707397).

The spelling of 181601216 in words is "one hundred eighty-one million, six hundred one thousand, two hundred sixteen".