181949 has 4 divisors (see below), whose sum is σ = 185436. Its totient is φ = 178464.

The previous prime is 181943. The next prime is 181957. The reversal of 181949 is 949181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 949181 = 937 ⋅1013.

It can be written as a sum of positive squares in 2 ways, for example, as 96100 + 85849 = 310^2 + 293^2 .

It is a cyclic number.

It is not a de Polignac number, because 181949 - 2⁸ = 181693 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181943) 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 in 3 ways as a sum of consecutive naturals, for example, 1664 + ... + 1769.

It is an arithmetic number, because the mean of its divisors is an integer number (46359).

2¹⁸¹⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

181949 is a deficient number, since it is larger than the sum of its proper divisors (3487).

181949 is an equidigital number, since it uses as much as digits as its factorization.

181949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3486.

The product of its digits is 2592, while the sum is 32.

The square root of 181949 is about 426.5548030441. The cubic root of 181949 is about 56.6652171871.

The spelling of 181949 in words is "one hundred eighty-one thousand, nine hundred forty-nine".