181281121 has 4 divisors (see below), whose sum is σ = 207178432. Its totient is φ = 155383812.

The previous prime is 181281103. The next prime is 181281127. The reversal of 181281121 is 121182181.

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: 121182181 = 151 ⋅802531.

It is a cyclic number.

It is not a de Polignac number, because 181281121 - 2⁷ = 181280993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181281127) 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, 12948645 + ... + 12948658.

It is an arithmetic number, because the mean of its divisors is an integer number (51794608).

Almost surely, 2^181281121 is an apocalyptic number.

It is an amenable number.

181281121 is a deficient number, since it is larger than the sum of its proper divisors (25897311).

181281121 is an equidigital number, since it uses as much as digits as its factorization.

181281121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25897310.

The product of its digits is 256, while the sum is 25.

The square root of 181281121 is about 13464.0677731509. The cubic root of 181281121 is about 565.9579863265.

The spelling of 181281121 in words is "one hundred eighty-one million, two hundred eighty-one thousand, one hundred twenty-one".