161660219 has 4 divisors (see below), whose sum is σ = 184754544. Its totient is φ = 138565896.

The previous prime is 161660209. The next prime is 161660221. The reversal of 161660219 is 912066161.

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

It is not a de Polignac number, because 161660219 - 2⁸ = 161659963 is a prime.

It is a super-2 number, since 2×161660219² = 52268052814255922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161660209) 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, 11547152 + ... + 11547165.

It is an arithmetic number, because the mean of its divisors is an integer number (46188636).

Almost surely, 2^161660219 is an apocalyptic number.

161660219 is a deficient number, since it is larger than the sum of its proper divisors (23094325).

161660219 is an equidigital number, since it uses as much as digits as its factorization.

161660219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23094324.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 161660219 is about 12714.5671967236. The cubic root of 161660219 is about 544.7547857387.

The spelling of 161660219 in words is "one hundred sixty-one million, six hundred sixty thousand, two hundred nineteen".