161649 has 8 divisors (see below), whose sum is σ = 239520. Its totient is φ = 107748.

The previous prime is 161641. The next prime is 161659. The reversal of 161649 is 946161.

161649 is a `hidden beast` number, since 1 + 616 + 49 = 666.

It is not a de Polignac number, because 161649 - 2³ = 161641 is a prime.

It is a super-2 number, since 2×161649² = 52260798402, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 5987 = 161649 / (1 + 6 + 1 + 6 + 4 + 9).

161649 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (161641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2967 + ... + 3020.

It is an arithmetic number, because the mean of its divisors is an integer number (29940).

2¹⁶¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

161649 is a deficient number, since it is larger than the sum of its proper divisors (77871).

161649 is an equidigital number, since it uses as much as digits as its factorization.

161649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5996 (or 5990 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 161649 is about 402.0559662535. The cubic root of 161649 is about 54.4742183699.

The spelling of 161649 in words is "one hundred sixty-one thousand, six hundred forty-nine".