11991105 has 32 divisors (see below), whose sum is σ = 24364800. Its totient is φ = 5481216.

The previous prime is 11991097. The next prime is 11991107. The reversal of 11991105 is 50119911.

11991105 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11991105 - 2³ = 11991097 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (11991107) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5400 + ... + 7289.

It is an arithmetic number, because the mean of its divisors is an integer number (761400).

Almost surely, 2^11991105 is an apocalyptic number.

11991105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11991105 is an abundant number, since it is smaller than the sum of its proper divisors (12373695).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11991105 is a wasteful number, since it uses less digits than its factorization.

11991105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12710 (or 12704 counting only the distinct ones).

The product of its (nonzero) digits is 405, while the sum is 27.

The square root of 11991105 is about 3462.8174944689. The cubic root of 11991105 is about 228.8862665658.

It can be divided in two parts, 1199 and 1105, that added together give a square (2304 = 48²).

The spelling of 11991105 in words is "eleven million, nine hundred ninety-one thousand, one hundred five".