161504819 has 4 divisors (see below), whose sum is σ = 184576944. Its totient is φ = 138432696.

The previous prime is 161504789. The next prime is 161504821. The reversal of 161504819 is 918405161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 918405161 = 17 ⋅54023833.

It is a cyclic number.

It is not a de Polignac number, because 161504819 - 2¹⁶ = 161439283 is a prime.

It is a super-2 number, since 2×161504819² = 52167613120445522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161506819) 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 3 ways as a sum of consecutive naturals, for example, 11536052 + ... + 11536065.

It is an arithmetic number, because the mean of its divisors is an integer number (46144236).

Almost surely, 2^161504819 is an apocalyptic number.

161504819 is a deficient number, since it is larger than the sum of its proper divisors (23072125).

161504819 is an equidigital number, since it uses as much as digits as its factorization.

161504819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23072124.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 161504819 is about 12708.4546267436. The cubic root of 161504819 is about 544.5801766434.

The spelling of 161504819 in words is "one hundred sixty-one million, five hundred four thousand, eight hundred nineteen".