12101805 has 20 divisors (see below), whose sum is σ = 21694332. Its totient is φ = 6454080.

The previous prime is 12101801. The next prime is 12101809. The reversal of 12101805 is 50810121.

12101805 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (12101801) and next prime (12101809).

It can be written as a sum of positive squares in 2 ways, for example, as 2683044 + 9418761 = 1638^2 + 3069^2 .

It is not a de Polignac number, because 12101805 - 2² = 12101801 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12101801) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 14536 + ... + 15345.

Almost surely, 2^12101805 is an apocalyptic number.

12101805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12101805 is a deficient number, since it is larger than the sum of its proper divisors (9592527).

12101805 is an equidigital number, since it uses as much as digits as its factorization.

12101805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29898 (or 29889 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 12101805 is about 3478.7648670182. The cubic root of 12101805 is about 229.5884575067.

Adding to 12101805 its reverse (50810121), we get a palindrome (62911926).

The spelling of 12101805 in words is "twelve million, one hundred one thousand, eight hundred five".