1643235161 has 16 divisors (see below), whose sum is σ = 1750502016. Its totient is φ = 1539073536.

The previous prime is 1643235151. The next prime is 1643235163. The reversal of 1643235161 is 1615323461.

It is a cyclic number.

It is not a de Polignac number, because 1643235161 - 2¹⁰ = 1643234137 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1643235163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 819386 + ... + 821388.

It is an arithmetic number, because the mean of its divisors is an integer number (109406376).

Almost surely, 2^1643235161 is an apocalyptic number.

It is an amenable number.

1643235161 is a deficient number, since it is larger than the sum of its proper divisors (107266855).

1643235161 is a wasteful number, since it uses less digits than its factorization.

1643235161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2752.

The product of its digits is 12960, while the sum is 32.

The square root of 1643235161 is about 40536.8370867782. The cubic root of 1643235161 is about 1180.0486336845.

The spelling of 1643235161 in words is "one billion, six hundred forty-three million, two hundred thirty-five thousand, one hundred sixty-one".