111100021 has 4 divisors (see below), whose sum is σ = 111140044. Its totient is φ = 111060000.

The previous prime is 111099997. The next prime is 111100027. The reversal of 111100021 is 120001111.

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

It can be written as a sum of positive squares in 2 ways, for example, as 31640625 + 79459396 = 5625^2 + 8914^2 .

It is a cyclic number.

It is not a de Polignac number, because 111100021 - 2⁷ = 111099893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111099977 and 111100013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111100027) 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, 15510 + ... + 21511.

It is an arithmetic number, because the mean of its divisors is an integer number (27785011).

Almost surely, 2^111100021 is an apocalyptic number.

It is an amenable number.

111100021 is a deficient number, since it is larger than the sum of its proper divisors (40023).

111100021 is an equidigital number, since it uses as much as digits as its factorization.

111100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40022.

The product of its (nonzero) digits is 2, while the sum is 7.

The square root of 111100021 is about 10540.3994706083. The cubic root of 111100021 is about 480.7338615290.

Adding to 111100021 its reverse (120001111), we get a palindrome (231101132).

The spelling of 111100021 in words is "one hundred eleven million, one hundred thousand, twenty-one".