161869665 has 32 divisors (see below), whose sum is σ = 275083776. Its totient is φ = 80998400.

The previous prime is 161869637. The next prime is 161869703. The reversal of 161869665 is 566968161.

It is not a de Polignac number, because 161869665 - 2⁵ = 161869633 is a prime.

It is a super-3 number, since 3×161869665³ (a number of 26 digits) contains 333 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 101464 + ... + 103046.

It is an arithmetic number, because the mean of its divisors is an integer number (8596368).

Almost surely, 2^161869665 is an apocalyptic number.

161869665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161869665 is a deficient number, since it is larger than the sum of its proper divisors (113214111).

161869665 is a wasteful number, since it uses less digits than its factorization.

161869665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2009.

The product of its digits is 466560, while the sum is 48.

The square root of 161869665 is about 12722.8009887760. The cubic root of 161869665 is about 544.9899445442.

It can be divided in two parts, 16 and 1869665, that added together give a palindrome (1869681).

The spelling of 161869665 in words is "one hundred sixty-one million, eight hundred sixty-nine thousand, six hundred sixty-five".