11551111 has 8 divisors (see below), whose sum is σ = 13570704. Its totient is φ = 9693120.

The previous prime is 11551103. The next prime is 11551117. The reversal of 11551111 is 11115511.

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

It is a cyclic number.

It is not a de Polignac number, because 11551111 - 2³ = 11551103 is a prime.

It is a Duffinian number.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11551117) 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, 40246 + ... + 40531.

It is an arithmetic number, because the mean of its divisors is an integer number (1696338).

Almost surely, 2^11551111 is an apocalyptic number.

11551111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11551111 is a deficient number, since it is larger than the sum of its proper divisors (2019593).

11551111 is a wasteful number, since it uses less digits than its factorization.

11551111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80801.

The product of its digits is 25, while the sum is 16.

The square root of 11551111 is about 3398.6925427287. The cubic root of 11551111 is about 226.0517737128.

Adding to 11551111 its reverse (11115511), we get a palindrome (22666622).

Subtracting from 11551111 its reverse (11115511), we obtain a square (435600 = 660²).

The spelling of 11551111 in words is "eleven million, five hundred fifty-one thousand, one hundred eleven".