161043643 has 4 divisors (see below), whose sum is σ = 164788888. Its totient is φ = 157298400.

The previous prime is 161043577. The next prime is 161043661. The reversal of 161043643 is 346340161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161043643 - 2²⁵ = 127489211 is a prime.

It is a super-2 number, since 2×161043643² = 51870109901422898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161043683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1872558 + ... + 1872643.

It is an arithmetic number, because the mean of its divisors is an integer number (41197222).

Almost surely, 2^161043643 is an apocalyptic number.

161043643 is a deficient number, since it is larger than the sum of its proper divisors (3745245).

161043643 is an equidigital number, since it uses as much as digits as its factorization.

161043643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3745244.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 161043643 is about 12690.2971990415. The cubic root of 161043643 is about 544.0613340502.

The spelling of 161043643 in words is "one hundred sixty-one million, forty-three thousand, six hundred forty-three".