161711911 has 4 divisors (see below), whose sum is σ = 161785512. Its totient is φ = 161638312.

The previous prime is 161711899. The next prime is 161711929. The reversal of 161711911 is 119117161.

161711911 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 161711911 - 2⁹ = 161711399 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161711911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161711111) 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, 33400 + ... + 37933.

It is an arithmetic number, because the mean of its divisors is an integer number (40446378).

Almost surely, 2^161711911 is an apocalyptic number.

161711911 is a deficient number, since it is larger than the sum of its proper divisors (73601).

161711911 is an equidigital number, since it uses as much as digits as its factorization.

161711911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73600.

The product of its digits is 378, while the sum is 28.

The square root of 161711911 is about 12716.5998207068. The cubic root of 161711911 is about 544.8128426181.

The spelling of 161711911 in words is "one hundred sixty-one million, seven hundred eleven thousand, nine hundred eleven".