11155551 has 16 divisors (see below), whose sum is σ = 16391808. Its totient is φ = 6692000.

The previous prime is 11155549. The next prime is 11155561. The reversal of 11155551 is 15555111.

It is a cyclic number.

It is not a de Polignac number, because 11155551 - 2¹ = 11155549 is a prime.

It is a super-2 number, since 2×11155551² = 248892636227202, which contains 22 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11155541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1660 + ... + 5006.

It is an arithmetic number, because the mean of its divisors is an integer number (1024488).

Almost surely, 2^11155551 is an apocalyptic number.

11155551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11155551 is a deficient number, since it is larger than the sum of its proper divisors (5236257).

11155551 is a wasteful number, since it uses less digits than its factorization.

11155551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3462.

The product of its digits is 625, while the sum is 24.

The square root of 11155551 is about 3339.9926646626. The cubic root of 11155551 is about 223.4414162125.

It can be divided in two parts, 1115 and 5551, that added together give a palindrome (6666).

The spelling of 11155551 in words is "eleven million, one hundred fifty-five thousand, five hundred fifty-one".