11987805 has 32 divisors (see below), whose sum is σ = 20715264. Its totient is φ = 5897216.

The previous prime is 11987783. The next prime is 11987837. The reversal of 11987805 is 50878911.

It is a cyclic number.

It is not a de Polignac number, because 11987805 - 2¹⁵ = 11955037 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13072 + ... + 13958.

It is an arithmetic number, because the mean of its divisors is an integer number (647352).

Almost surely, 2^11987805 is an apocalyptic number.

11987805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11987805 is a deficient number, since it is larger than the sum of its proper divisors (8727459).

11987805 is a wasteful number, since it uses less digits than its factorization.

11987805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 965.

The product of its (nonzero) digits is 20160, while the sum is 39.

The square root of 11987805 is about 3462.3409710772. The cubic root of 11987805 is about 228.8652678343.

The spelling of 11987805 in words is "eleven million, nine hundred eighty-seven thousand, eight hundred five".