181364649 has 4 divisors (see below), whose sum is σ = 241819536. Its totient is φ = 120909764.

The previous prime is 181364629. The next prime is 181364657. The reversal of 181364649 is 946463181.

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: 946463181 = 3 ⋅315487727.

It is a cyclic number.

It is not a de Polignac number, because 181364649 - 2¹⁵ = 181331881 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 181364649.

It is not an unprimeable number, because it can be changed into a prime (181364629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30227439 + ... + 30227444.

It is an arithmetic number, because the mean of its divisors is an integer number (60454884).

Almost surely, 2^181364649 is an apocalyptic number.

It is an amenable number.

181364649 is a deficient number, since it is larger than the sum of its proper divisors (60454887).

181364649 is an equidigital number, since it uses as much as digits as its factorization.

181364649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60454886.

The product of its digits is 124416, while the sum is 42.

The square root of 181364649 is about 13467.1693016758. The cubic root of 181364649 is about 566.0448975276.

The spelling of 181364649 in words is "one hundred eighty-one million, three hundred sixty-four thousand, six hundred forty-nine".