1115561111 has 8 divisors (see below), whose sum is σ = 1330358784. Its totient is φ = 914621400.

The previous prime is 1115561093. The next prime is 1115561123. The reversal of 1115561111 is 1111655111.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1115561111 - 2⁶ = 1115561047 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1115561141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3464315 + ... + 3464636.

It is an arithmetic number, because the mean of its divisors is an integer number (166294848).

Almost surely, 2^1115561111 is an apocalyptic number.

1115561111 is a deficient number, since it is larger than the sum of its proper divisors (214797673).

1115561111 is an equidigital number, since it uses as much as digits as its factorization.

1115561111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6928981.

The product of its digits is 150, while the sum is 23.

The square root of 1115561111 is about 33400.0166317324. The cubic root of 1115561111 is about 1037.1250452491.

The spelling of 1115561111 in words is "one billion, one hundred fifteen million, five hundred sixty-one thousand, one hundred eleven".