161281541 has 4 divisors (see below), whose sum is σ = 163553184. Its totient is φ = 159009900.

The previous prime is 161281531. The next prime is 161281553. The reversal of 161281541 is 145182161.

161281541 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 145182161 = 9187 ⋅15803.

It is a cyclic number.

It is not a de Polignac number, because 161281541 - 2¹⁰ = 161280517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161281501) 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, 1135715 + ... + 1135856.

It is an arithmetic number, because the mean of its divisors is an integer number (40888296).

Almost surely, 2^161281541 is an apocalyptic number.

It is an amenable number.

161281541 is a deficient number, since it is larger than the sum of its proper divisors (2271643).

161281541 is an equidigital number, since it uses as much as digits as its factorization.

161281541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2271642.

The product of its digits is 1920, while the sum is 29.

The square root of 161281541 is about 12699.6669641373. Note that the first 3 decimals coincide. The cubic root of 161281541 is about 544.3291029192.

The spelling of 161281541 in words is "one hundred sixty-one million, two hundred eighty-one thousand, five hundred forty-one".