161001111 has 4 divisors (see below), whose sum is σ = 214668152. Its totient is φ = 107334072.

The previous prime is 161001107. The next prime is 161001133. The reversal of 161001111 is 111100161.

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

It is not a de Polignac number, because 161001111 - 2² = 161001107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161001161) 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, 26833516 + ... + 26833521.

It is an arithmetic number, because the mean of its divisors is an integer number (53667038).

Almost surely, 2^161001111 is an apocalyptic number.

161001111 is a deficient number, since it is larger than the sum of its proper divisors (53667041).

161001111 is an equidigital number, since it uses as much as digits as its factorization.

161001111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53667040.

The product of its (nonzero) digits is 6, while the sum is 12.

The square root of 161001111 is about 12688.6213199071. The cubic root of 161001111 is about 544.0134338793.

Adding to 161001111 its reverse (111100161), we get a palindrome (272101272).

The spelling of 161001111 in words is "one hundred sixty-one million, one thousand, one hundred eleven".