161206505 has 16 divisors (see below), whose sum is σ = 201268800. Its totient is φ = 123802560.

The previous prime is 161206459. The next prime is 161206519. The reversal of 161206505 is 505602161.

It is not a de Polignac number, because 161206505 - 2⁸ = 161206249 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22850 + ... + 29060.

It is an arithmetic number, because the mean of its divisors is an integer number (12579300).

Almost surely, 2^161206505 is an apocalyptic number.

It is an amenable number.

161206505 is a deficient number, since it is larger than the sum of its proper divisors (40062295).

161206505 is a wasteful number, since it uses less digits than its factorization.

161206505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6424.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 161206505 is about 12696.7123697436. The cubic root of 161206505 is about 544.2446737192.

Adding to 161206505 its reverse (505602161), we get a palindrome (666808666).

The spelling of 161206505 in words is "one hundred sixty-one million, two hundred six thousand, five hundred five".