111628409 has 4 divisors (see below), whose sum is σ = 118194804. Its totient is φ = 105062016.

The previous prime is 111628403. The next prime is 111628417. The reversal of 111628409 is 904826111.

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 70090384 + 41538025 = 8372^2 + 6445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111628409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111628403) 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, 3283172 + ... + 3283205.

It is an arithmetic number, because the mean of its divisors is an integer number (29548701).

Almost surely, 2^111628409 is an apocalyptic number.

It is an amenable number.

111628409 is a deficient number, since it is larger than the sum of its proper divisors (6566395).

111628409 is an equidigital number, since it uses as much as digits as its factorization.

111628409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6566394.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 111628409 is about 10565.4346337479. The cubic root of 111628409 is about 481.4947745871.

The spelling of 111628409 in words is "one hundred eleven million, six hundred twenty-eight thousand, four hundred nine".