161211719 has 4 divisors (see below), whose sum is σ = 161644296. Its totient is φ = 160779144.

The previous prime is 161211707. The next prime is 161211733. The reversal of 161211719 is 917112161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 917112161 = 7 ⋅131016023.

It is a cyclic number.

It is not a de Polignac number, because 161211719 - 2⁴ = 161211703 is a prime.

It is a super-2 number, since 2×161211719² = 51978436685869922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161211691 and 161211700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161211779) 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, 215729 + ... + 216474.

It is an arithmetic number, because the mean of its divisors is an integer number (40411074).

Almost surely, 2^161211719 is an apocalyptic number.

161211719 is a deficient number, since it is larger than the sum of its proper divisors (432577).

161211719 is an equidigital number, since it uses as much as digits as its factorization.

161211719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432576.

The product of its digits is 756, while the sum is 29.

The square root of 161211719 is about 12696.9176968271. The cubic root of 161211719 is about 544.2505412681.

It can be divided in two parts, 1612 and 11719, that added together give a palindrome (13331).

The spelling of 161211719 in words is "one hundred sixty-one million, two hundred eleven thousand, seven hundred nineteen".