105721111 has 4 divisors (see below), whose sum is σ = 111285400. Its totient is φ = 100156824.

The previous prime is 105721103. The next prime is 105721123. The reversal of 105721111 is 111127501.

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 105721111 - 2³ = 105721103 is a prime.

It is a super-2 number, since 2×105721111² = 22353906622148642, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 5564269 = 105721111 / (1 + 0 + 5 + 7 + 2 + 1 + 1 + 1 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105721151) 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, 2782116 + ... + 2782153.

It is an arithmetic number, because the mean of its divisors is an integer number (27821350).

Almost surely, 2^105721111 is an apocalyptic number.

105721111 is a deficient number, since it is larger than the sum of its proper divisors (5564289).

105721111 is an equidigital number, since it uses as much as digits as its factorization.

105721111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5564288.

The product of its (nonzero) digits is 70, while the sum is 19.

The square root of 105721111 is about 10282.0771734120. The cubic root of 105721111 is about 472.8469290308.

Adding to 105721111 its reverse (111127501), we get a palindrome (216848612).

The spelling of 105721111 in words is "one hundred five million, seven hundred twenty-one thousand, one hundred eleven".