161543889409 has 16 divisors (see below), whose sum is σ = 189482544000. Its totient is φ = 134866917504.

The previous prime is 161543889407. The next prime is 161543889413. The reversal of 161543889409 is 904988345161.

It is a cyclic number.

It is not a de Polignac number, because 161543889409 - 2¹ = 161543889407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161543889407) 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, 1893334 + ... + 1976815.

It is an arithmetic number, because the mean of its divisors is an integer number (11842659000).

Almost surely, 2^161543889409 is an apocalyptic number.

It is an amenable number.

161543889409 is a deficient number, since it is larger than the sum of its proper divisors (27938654591).

161543889409 is an equidigital number, since it uses as much as digits as its factorization.

161543889409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3870312.

The product of its (nonzero) digits is 7464960, while the sum is 58.

The spelling of 161543889409 in words is "one hundred sixty-one billion, five hundred forty-three million, eight hundred eighty-nine thousand, four hundred nine".