161829681 has 16 divisors (see below), whose sum is σ = 246040704. Its totient is φ = 93729024.

The previous prime is 161829677. The next prime is 161829697. The reversal of 161829681 is 186928161.

It is not a de Polignac number, because 161829681 - 2² = 161829677 is a prime.

It is a super-2 number, since 2×161829681² = 52377691305123522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161829781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121381 + ... + 122706.

It is an arithmetic number, because the mean of its divisors is an integer number (15377544).

Almost surely, 2^161829681 is an apocalyptic number.

It is an amenable number.

161829681 is a deficient number, since it is larger than the sum of its proper divisors (84211023).

161829681 is a wasteful number, since it uses less digits than its factorization.

161829681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244120.

The product of its digits is 41472, while the sum is 42.

The square root of 161829681 is about 12721.2295396318. The cubic root of 161829681 is about 544.9450675492.

The spelling of 161829681 in words is "one hundred sixty-one million, eight hundred twenty-nine thousand, six hundred eighty-one".