161281505 has 24 divisors (see below), whose sum is σ = 243128256. Its totient is φ = 100536480.

The previous prime is 161281501. The next prime is 161281513. The reversal of 161281505 is 505182161.

It is not a de Polignac number, because 161281505 - 2² = 161281501 is a prime.

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 23 ways as a sum of consecutive naturals, for example, 14807 + ... + 23276.

It is an arithmetic number, because the mean of its divisors is an integer number (10130344).

Almost surely, 2^161281505 is an apocalyptic number.

It is an amenable number.

161281505 is a deficient number, since it is larger than the sum of its proper divisors (81846751).

161281505 is a wasteful number, since it uses less digits than its factorization.

161281505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38117 (or 38106 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 29.

The square root of 161281505 is about 12699.6655467772. The cubic root of 161281505 is about 544.3290624189.

The spelling of 161281505 in words is "one hundred sixty-one million, two hundred eighty-one thousand, five hundred five".