161919 has 10 divisors (see below), whose sum is σ = 242000. Its totient is φ = 107892.

The previous prime is 161911. The next prime is 161921. The reversal of 161919 is 919161.

It is not a de Polignac number, because 161919 - 2³ = 161911 is a prime.

It is a super-2 number, since 2×161919² = 52435525122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161892 and 161901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161911) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 919 + ... + 1080.

It is an arithmetic number, because the mean of its divisors is an integer number (24200).

2¹⁶¹⁹¹⁹ is an apocalyptic number.

161919 is a deficient number, since it is larger than the sum of its proper divisors (80081).

161919 is an equidigital number, since it uses as much as digits as its factorization.

161919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2011 (or 2002 counting only the distinct ones).

The product of its digits is 486, while the sum is 27.

The square root of 161919 is about 402.3916003099. The cubic root of 161919 is about 54.5045306673.

The spelling of 161919 in words is "one hundred sixty-one thousand, nine hundred nineteen".