161121686443 has 2 divisors, whose sum is σ = 161121686444. Its totient is φ = 161121686442.

The previous prime is 161121686431. The next prime is 161121686533. The reversal of 161121686443 is 344686121161.

It is a weak prime.

It is an emirp because it is prime and its reverse (344686121161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161121686443 - 2⁹ = 161121685931 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161121686443.

It is not a weakly prime, because it can be changed into another prime (161121684443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80560843221 + 80560843222.

It is an arithmetic number, because the mean of its divisors is an integer number (80560843222).

Almost surely, 2^161121686443 is an apocalyptic number.

161121686443 is a deficient number, since it is larger than the sum of its proper divisors (1).

161121686443 is an equidigital number, since it uses as much as digits as its factorization.

161121686443 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 43.

The spelling of 161121686443 in words is "one hundred sixty-one billion, one hundred twenty-one million, six hundred eighty-six thousand, four hundred forty-three".