161784969919 has 2 divisors, whose sum is σ = 161784969920. Its totient is φ = 161784969918.

The previous prime is 161784969821. The next prime is 161784969947. The reversal of 161784969919 is 919969487161.

It is a strong prime.

It is an emirp because it is prime and its reverse (919969487161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161784969919 - 2¹³ = 161784961727 is a prime.

It is a super-2 number, since 2×161784969919² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161784969989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80892484959 + 80892484960.

It is an arithmetic number, because the mean of its divisors is an integer number (80892484960).

Almost surely, 2^161784969919 is an apocalyptic number.

161784969919 is a deficient number, since it is larger than the sum of its proper divisors (1).

161784969919 is an equidigital number, since it uses as much as digits as its factorization.

161784969919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52907904, while the sum is 70.

The spelling of 161784969919 in words is "one hundred sixty-one billion, seven hundred eighty-four million, nine hundred sixty-nine thousand, nine hundred nineteen".